EP0485426A1 - Opto-electronic component having a positioned optical fiber associated therewith - Google Patents

Opto-electronic component having a positioned optical fiber associated therewith

Info

Publication number
EP0485426A1
EP0485426A1 EP90911437A EP90911437A EP0485426A1 EP 0485426 A1 EP0485426 A1 EP 0485426A1 EP 90911437 A EP90911437 A EP 90911437A EP 90911437 A EP90911437 A EP 90911437A EP 0485426 A1 EP0485426 A1 EP 0485426A1
Authority
EP
European Patent Office
Prior art keywords
opto
arm
arms
electronic component
fiber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP90911437A
Other languages
German (de)
French (fr)
Other versions
EP0485426A4 (en
Inventor
Melvin Harry Johnson
Jerald Dana Lee
Frank Marsden Willis
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EIDP Inc
Original Assignee
EI Du Pont de Nemours and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by EI Du Pont de Nemours and Co filed Critical EI Du Pont de Nemours and Co
Publication of EP0485426A1 publication Critical patent/EP0485426A1/en
Publication of EP0485426A4 publication Critical patent/EP0485426A4/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24Coupling light guides
    • G02B6/42Coupling light guides with opto-electronic elements
    • G02B6/4201Packages, e.g. shape, construction, internal or external details
    • G02B6/4204Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24Coupling light guides
    • G02B6/26Optical coupling means
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24Coupling light guides
    • G02B6/36Mechanical coupling means
    • G02B6/3628Mechanical coupling means for mounting fibres to supporting carriers
    • G02B6/3632Mechanical coupling means for mounting fibres to supporting carriers characterised by the cross-sectional shape of the mechanical coupling means
    • G02B6/3636Mechanical coupling means for mounting fibres to supporting carriers characterised by the cross-sectional shape of the mechanical coupling means the mechanical coupling means being grooves
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24Coupling light guides
    • G02B6/42Coupling light guides with opto-electronic elements
    • G02B6/4201Packages, e.g. shape, construction, internal or external details
    • G02B6/4202Packages, e.g. shape, construction, internal or external details for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24Coupling light guides
    • G02B6/36Mechanical coupling means
    • G02B6/3628Mechanical coupling means for mounting fibres to supporting carriers
    • G02B6/3648Supporting carriers of a microbench type, i.e. with micromachined additional mechanical structures
    • G02B6/3652Supporting carriers of a microbench type, i.e. with micromachined additional mechanical structures the additional structures being prepositioning mounting areas, allowing only movement in one dimension, e.g. grooves, trenches or vias in the microbench surface, i.e. self aligning supporting carriers
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24Coupling light guides
    • G02B6/36Mechanical coupling means
    • G02B6/3628Mechanical coupling means for mounting fibres to supporting carriers
    • G02B6/3684Mechanical coupling means for mounting fibres to supporting carriers characterised by the manufacturing process of surface profiling of the supporting carrier
    • G02B6/3692Mechanical coupling means for mounting fibres to supporting carriers characterised by the manufacturing process of surface profiling of the supporting carrier with surface micromachining involving etching, e.g. wet or dry etching steps

Definitions

  • the present invention relates to an opto-electronic component having a positioning apparatus for positioning the center of an optical fiber along a predetermined reference axis of an opto-electronic device independently of variations in the outside diameter of the fiber.
  • a typical expedient used in such devices is a generally V-shaped groove that is formed in a substrate material and which serves as a cradle to accept the fiber being positioned.
  • Representative of such devices is that shown in United States Patent 4,756,591 (Fischer et al.), wherein a V-groove is formed in a silicon substrate and an elastomeric member is biased against the fiber to hold it in the groove.
  • the groove may be stepped to provide a deeper groove segment to hold the jacket of the fiber within the device.
  • Patent 4,756,591 discloses a grooved silicon substrate having a pair of intersecting V- grooves therein.
  • a fiber to be positioned is disposed in one of the grooves while a shim is disposed in the other of the grooves.
  • the shim may take the form of a tapered or an eccentric fiber, which when respectively slid or rotated under the first fiber serves lo lift the same lo bring the * axis thereof into alignment with a reference axis.
  • a cover may be positioned above the substrate to assist in clamping the first fiber into position.
  • United States Patent 4,802,727 also discloses a positioning arrangement for optical components and waveguides which utilizes a V-grooved struclure.
  • United States Patent 4,826,272 Patentella et al.
  • United States Patent 4,830,450 discloses arrangements for positioning an optical fiber that utilize members having frusloconical apertures therethrough.
  • single crystalline silicon is the material of choice of the devices above mentioned because of the proclivity of crystalline silicon to be etched along precise crystallographic planes, thus forming precise grooves or structural features by photolithographic microfabrication techniques.
  • Etchants exist that act upon a selected crystallographic plane to a differential degree than upon an adjacent plane, permitting the needed precise control.
  • V- grooves in particular, can be etched to a controlled width and truncated depth. Under some conditions V-grooves may be etched in a self-limiting operation.
  • the photolithographic microfabrication process is generally described by Brodie and Muray, "The Physics of Microfabrication", Plenum Publishing, New York (1982).
  • Optical fibers include an inner core having a predetermined index of refraction surrounded by a cladding layer of a lower index.
  • the inner core is the medium in which the optical energy is guided, while the cladding layer defines the index boundary with the core.
  • the outer diameter of the fiber may vary in dimension about a predetermined nominal dimension. Il has been seen, f f example, that two nominally identical fibers from the same manufacturer may vary in outside diametrical dimension by as much as plus or minus four (4) micrometers. This fiber to fiber variation in outer diameter makes difficult the accurate positioning of the axis of the core of a fiber with respect to a predetermined reference axis.
  • the present invention relates to a relates to an opto- electronic component having a positioning apparatus for positioning the center of an optical fiber along a predetermined reference axis of an opto-electronic device independently of variations in the outside diameter of the fiber.
  • the opto ⁇ electronic device can take the form of a solid state laser or a solid state light responsive diode such as a photodiode.
  • the opto-electronic device can be an edge active or a surface active device.
  • the optical fiber can be a single-mode or a multi-mode fiber.
  • the positi ning apparatus includes a first and a second arm, each of which has at least a first and a second sidewall that cooperate to define a groove therein.
  • the groove in each arm is preferably a converging groove so that when the arms are arranged in superimposed relationship the converging grooves cooperate to define a funnel-like channel over at least a predetermined portion of its length.
  • the channel has an inlet end and an outfet end and a reference axis extending therethrough.
  • a fiber introduced into the inlet end of the channel with its axis spaced from the reference axis is displacable by contact with at least one of the sidewalls on one of the arms to place a predetermined point on an end face of the member into alignment with the reference axis where it is there held by contact with the first and second arms.
  • each of the first and the second arms includes a trough therein, each trough being disposed on an arm a predetermined distance behind the groove in that arm, so that in the closed position the troughs cooperate to define a guideway.
  • the arms having the converging grooves therein may, as is preferred, be movable from a first, closed, position to a second, centering, position.
  • the superimposed arms are, in this instance, mounted cantilevered fashion, to a foundation.
  • Means is provided for biasing each of the arms with a substantially equal and oppositely directed biasing force toward the first position.
  • the biasing means comprises a reduced thickness portion in each of the first and the second arms, the reduced thickness portion defining a flexure in each arm which, when each arm is deflected by contact with the cylindrical member, generates a force on each arm to bias each arm toward the closed position.
  • the present invention encompasses any positioning apparatus having arms that are movable whether the groove in each arm take the form of a converging groove or £ groove of an alternate Torm. Alternately, the present invention also encompasses any positioning apparatus in which the groove in each arm is converging in form, whether the arms are movable or fixed with respect to each other.
  • the positioning apparatus be fabricated from a crystalline material, such as single crystal silicon, using microfabrication techniques.
  • a crystalline material such as single crystal silicon
  • Each structural element of the positioning apparatus (viz., each of the arms ar ⁇ d each foundation) is fabricated in mass on a wafer of silicon. The finished wafer are aligned, superimposed, and bonded, and each of the resulting positioning apparatus
  • Figure 1 is a perspective, exploded view of a positioning apparatus in accordance with the preferred embodiment of the present invention for positioning the center point on the end face of an optical fiber with respect to a predetermined reference axis;
  • Figure 2 is a perspective view of the positioning apparatus of Figure 1 in the fully assembled condition
  • Figure 3 is a front elevation view of the assembled positioning apparatus of Figures 1 and 2, taken along view lines 3-3 in Figure 2;
  • Figure 4 is a sectional view, in elevation, of the assembled positioning apparatus of Figure 2, taken along section lines 4-4 in that Figure illustrating the truncated V-groove therein;
  • Figure 4A is a view generally similar to Figure 4 in which a full V-groove is formed in the positioning apparatus while Figure 4B is a view generally similar to Figure 4 in which both a full V-groove and a truncated V-groove are formed;
  • Figure 5 is a plan view one of the arms of the positioning apparatus of Figure 1 illustr iting the relationships of the axes of the groove and the guideway therein;
  • Figures 6A and 6B, 7A and 7B, and 8A and 8B are diagrammatic elevational and end views of the action of the clips disposed on the arms of the positioning apparatus shown in Figures 1 and 2 in response to the introduction of a fiber thereinto;
  • Figures 9 and 10 are exploded and assembled perspective views, generally similar to Figures 1 and 2, of another alternate embodiment of a positioning device in accordance with the present invention in hich the arms have nonconverging grooves therein and in which the arms are articulably movable with respect to each other along one axis only;
  • Figures 11 are 12 are sectional views taken along section lines 1 1-1 1 and 12-12 in Figure 10;
  • Figures 13 and 14 are exploded and assembled perspective views, generally similar to Figures 1 and 2, of another alternate embodiment of a positioning device in accordance with the present invention in which only one of the arms has a nonconverging groove therein and in which both of the arms are articulably movable with respect to each other;
  • Figures 15 are 16 are sectional views taken along section lines 15-15 and 16-16 in Figure 14;
  • Figures 17 and 18 are exploded and assembled perspective views, generally similar lo Figures 1 and 2, of an alternate embodiment of a positioning device in accordance with the present invention in which the arms have converging grooves therein and in which the arms are fixed with respect to each olher;
  • Figure 19 is an end view taken along view lines 19-19 in Figure 18;
  • Figure 20 is a side sectional view, taken along view lines 20-20 in Figure 18, illustrating the position of the fiber within the channel of the a positioning apparatus in accordance with the alternate embodiment of the invention shown therein;
  • Figure 21 is an exploded isometric view of a pair of positioning apparatus as shown in Figure 1 used to form a fiber-to-fiber connector in accordance with the present invention while Figure 22 is an isometric view of the fully assembled connector of Figure 21 ;
  • Figures 23 and 24 are, respectively, a top view in section and a side elevation section view of a pair of positioning apparatus in accordance the embodiment of the invention as shown in Figure 17 used to form a fiber-to-fiber connector in accordance with the present invention;
  • Figures 25 and 26 are isometric views of a housing used for the fiber-to-fiber connector shown in Figures 21 and 22 in the open and in the partially closed positions, respectively, while Figure 27 is a section view of the housing of Figure 25 in the fully closed position taken along section lines 27-27 of Figure 26;
  • Figure 28 is a section view generally similar to Figure 27 of a housing used for the fiber-to-fiber connector shown in Figure 24;
  • Figure 29 is a isometric view of an alternate housing for a fiber-to-fiber connector formed of a pair of positioning apparatus
  • Figures 30 and 31 are isometric exploded and assembled views, respectively, illustrating the use of a positioning 10
  • Figure 31 A is a side elevational view generally similar to
  • FIG. 31 showing a positioning apparatus in accordance with the present invention positioning a lens with respect to an opto-electronic component
  • Figures 32 and 33 tire isometric exploded and assembled views, respectively, generally similar to Figures 30 and 31 , illustrating the use of a positioning apparatus in in accordance with the present invention to position an optical fiber with respect to the axis of a device having active surface device, in which the device is edge mounted;
  • Figure 34 is a perspective view of a wafer used used to fabricate a plurality of arms or foundations used in a positioning apparatus, in accordance with the present invention.
  • Figure 35 is a perspective view of a mask used in the photolithographic process forming a plurality of arms or foundations for a positioning apparatus in accordance with the present invention
  • Figure 36 is an enlarged view of a portion of the mask used for creating a plurality of arms on the wafer 34;
  • Figures 37A through 37E are schematic representations of the process steps effected during fabricalion of the wafer.
  • Figure 38 is is an enlarged view of a portion of the mask used for creating solder masks on the wafer;
  • Figure 39 is an enlarged view of a portion of the mask used for creating foundations on the wafer;
  • Figures 40A through 40D are schematic representations of the steps used to form a plurality of fiber-lo-fiber connectors from superimposed wafers having the arms and foundations thereon;
  • Figure 41 is a definitional drawing illustrating the characteristics of a converging groove as that term is used in this application.
  • Figures 42A through 42F are end views showing alternate arrangements of movable arms each holding a cylindrical member along at least three contact points in accordance with the present invention.
  • a positioning apparatus generally by reference character 20 in accordance with the present invention is shown in an exploded and in a fully assembled condition.
  • the positioning apparatus 20 is microfabricaled from single crystal silicon or another differentially etchable single crystal material. These materials are preferred because they permit the accurate formation of the structural features of the apparatus 20 using the process of differential etching.
  • the positioning apparatus 20 is useful in accurately positioning a predetermined point on the end face of a cylindrical member, typically a point on the central axis of the member, along a rejje en e axis.
  • this reference axis is itself collinearly aligned with respect to another axis, as an operative axis of a device operably associable with the cylindrical member.
  • the description of the cylindrical member is cast in terms of an optical fiber, but it is to be understood thai the present invention may be effectively utilized with any other member having the form of small diameter cylindrical object.
  • the positioning apparatus invention may be used to position a point on the end face of a length of microlubing or capillajy tubing.
  • small diameter it is generally meant less than 0,04 inch (one (1) millimeter), but usually less than 0.020 inch.
  • the term cylindrical is not to be strictly limited to an object having a completely circular outer configuration, but would apply to any object whose outer contour is symmetrical to its central axis.
  • the positioning apparatus of the present invention may be used to position a point on the end face of a polygonal shaped member or an elliptical member.
  • the cylindrical member preferably takes the form of an optical fiber.
  • the positioning apparatus of the present invention is particularly adapted to place a predetermined point P on the end face E of an optical fiber F along a predetermined refererice axis R.
  • the point P is the geometric center and Ifes on the axis A of the core C ( Figures 6A and 6B) of the fiber F.
  • the core C is itself surrounded by an outer cladding layer L.
  • a jacket J is provided about the cladding layer L but is stripped from the fiber F prior to the insertion of the fiber into the positioning apparatus 20.
  • the jacket may comprise more than one layer.
  • the dimension of the outer diameter D of the cladding layer L of the fiber F may vary from fiber to fiber.
  • the fiber may be a single-mode or a multi-mode fiber.
  • the positioning capability of the positioning apparatus 20 is especially adaplec for positioning the point P of a single mode fiber within the precise tolerances required to effectively couple light emanating from the single mode fiber into another fiber or lo position the fiber with respect to an optical device.
  • the positioning apparatus 20 includes a first and a second arm 22A, 22B, respectively.
  • each of the arms 22A, 22B is identically formed in manner to be discussed, so the structural details of only one of the arms, e. g., the arm 22A, will be discussed. It should be apparent, however, that each structural detail of the arm 22A finds a counterpart in the other arm 22B. Accordingly, corresponding reference numerals with the appropriate alphabet suffix will denote corresponding structural details on lb ; arm 22B. If the arms are not substantially identical (as, for example, in the embodiments of Figures 13 through 16 and Figure 42) adjustments must be made to provide the requisite biasing forces to maintain the point P on the reference axis R
  • the arm 22A incudes a base portion 24A having a first major surface 26A and a second, opposed, major surface 28A.
  • the base portion 24A extends along the full length of the arm 22A and the dimension of the central region 25A of the base portic n 24A defines the basic dimension of the arm 22A.
  • a clip generally indicated by the reference character 30A is defined at a first end of the arm 22A.
  • the clip 30A is formed in a relatively thicker abutment portion 32A that lies on the first surface 26A of the arm 22A.
  • the abutment 32A has a planar surface 34A thereon that preferably lies parallel to the first major surface 26A.
  • the arm 22A has an overall length dimension on the order of twenty eight hundred (2800) micrometers and a width on the order of three hundred fifty (350) micrometers. In the central region 25A the arm 22A has a thickness dimension on the order of fifty (50) micrometers, while the remaining portion of the arm 22A has a thickness dimension on the order of one hundred twenty five (125) micrometers.
  • a generally converging V-shaped groove 36A is defined in the abutment 32A of the clip 30A by generally planar first and second sidewalls 38A, 40A, respectively, and the forward end region of the first surface 26A of the base 24A.
  • the sidewall 38A has an upper edge 39A ( Figure 1) thereon while the sidewall 40A has an upper edge 41 A thereon.
  • plane is meant to encompass a surface formed in a single crystal material by etching in which microscopic steps are of necessity produced owing to the lattice structure of the crystal.
  • a “converging” groove is a groove 36 defined from at least two planar sidewalls 38, 40 and has an enlarged inlet end 42A and a narrower outlet end 43A.
  • the respective upper edges 39, 41 of the sidewalls 38, 40 of the groove 36 lie in a reference plane RP having a reference axis R lying therein.
  • the planar surfaces 34 also lie in the reference plane RP.
  • the reference axis R extends in the reference plane RP from the inlet end 42 to the the outlet end 43 of the groove 36.
  • Each point on the reference axis R is spaced in the reference plane RP an equal distance from the respective upper edges 39, 41 of the sidewalls 38, 40.
  • the distance between the upper edges of the sidewalls decreases from the inlet end 42 to the outlet end 43 of the groove 36.
  • the surfaces of the sidewalls 38, 40 are equally and oppositely inclined with respect to the reference plane at an angle A greater than zero and less than ninety degrees.
  • the angle of inclination A is determined by the lattice structure of the crystal, and in the case of (100) silicon, is 54.74 degrees.
  • the projections of the sidewalls 38, 40 intersect in a line L that itself intersects the reference axis R forwardly past the outlet end 43 of the groove 36.
  • the line L is inclined with respect to the reference plane RP at an angle B that is greater than zero degrees but less than ninety degrees.
  • the upper edges 39, 41 of the sidewalls 38, 40 each converge toward the reference axis R at an angle C that is on the order of two and one-half to five degrees (2.5 to 5) degrees, and most preferably at about three (3) degrees.
  • the angle B is dependent upon the values of the angles A and C and tyoically the angle B lies in the ange from about four (4) to five (5) degrees.
  • a "fully funnel-like" channel is a channel that is defined by the cooperative association of at least two converging grooves.
  • a “partially funnel-like” channel is a channel that is defined by one converging groove and a surface.
  • a "uniform width" groove is jne in which each point on the reference axis R is spaced in the reference plane RP a uniform distance from the edges 39, 41 of the sidewalls 38, 40 as one progresses from the inlet end 42 to the outlet end 43 of the groove 36.
  • the sidewalls of a uniform width groove may be inclined with respect to reference plane RP, or they may extend perpendicularly to it, as desired.
  • a channel formed from one or two uniform widtfr gr ⁇ ove(s) is termed a "uniform width" channel.
  • Such a; channel may have a rectangular cross section in a plane perpendicular both to the reference plane and to the reference axis, assuming no inclination of the sidewalls of the groove.
  • a tapering groove is one in which the planar sidewalls are perpendicular to he reference plane but the distance in the reference plane between the reference axis and the edges of the sidewalls decreases as one progresses from the inlet to the outlet of the groove such that the extensions of the planar sidewalls intersect in a line that itself intersects perpendicularly with the reference axis.
  • the groove 36 is a converging groove, and more preferably, is a V- groove truncated by the presence of a third sidewall defined by a portion of the major surface 26 of the arm 22 in which it is disposed.
  • the truncated V-groove has the same depth throughout its length, when measured along a dimension line erected perpendicular to the surface 34A of the abutment 32A in a direction extending toward the major surface 26A.
  • V-shape of the groove 36A may take alternate fotpts and remain within the
  • the groove 36A may be defined by only the first and second sidewalls 38A, 40A, respectively, in which event the groove 36A appears as a full V-shape throughout its length.
  • FIG. 4B shows another alternative arrangement in which a truncated V-groove (defined by the first and second sidew; s 38A, 40A, respectively, end the portion of the major surface 26A) extends for some predetermined axial distance while a full V-groove (defined by the first and second sidewalls 38A, 40A, respectively) extends for some second predetermined distance.
  • a truncated V-groove defined by the first and second sidew; s 38A, 40A, respectively, end the portion of the major surface 26A
  • a full V-groove defined by the first and second sidewalls 38A, 40A, respectively
  • the groove 36A does not converge throughout the full a. 1 distance through the abutment 32A.
  • the sidewalls 38A, 40A defining the groove 36A do not converge throughout the full length of the groove, but define a short uniform width portion just past the converging portion of the groove 36A.
  • the overall axial length of the groove 36 (including both the converging and the uniform width portit ) is on the order of three tenths (0.3) of a millimeter, while the uniform width portion of the groove occupies an axial length of one tenth (0.1 ) oi a mi' ⁇ meter.
  • the converging and nonconverging portions of the groove 36A have a common axis . )A associated therewith.
  • an extended enlargement region 54A having a planar surface 56A lies on the base portion 24A of the arm 22A spaced a predetermined axial distance 58A behind the abutment 32A.
  • the 58A is on the order j ⁇ f one (1 ) millimeter.
  • the surface 56A is coplanar wilh the surface 34A.
  • the enlargement 54A is provided wilh a nonconverging, uniform width, truncated V- shaped trough 60A defined by inclined planar sidewalls 62A, 64A, respectively, and by a portion of the major surface 26A of the base portion 24A near the second end thereof.
  • the trough 60A is uniform in depth along its axial length, as measured with respect lo a dimension line erected perpendicular to the surface 56A toward the major surface 26A.
  • the trough 60A communicates with a converging lead-in 68A.
  • the walls 62A, 64A may be inclined with respect to each other so that the trough 60A may be a full V-shape or a partial V- shape, similar to the situation illustrated in connection with Figures 4A and 4B for the .groove 36A.
  • the walls 62A, 64A defining the troughs 60A, 60B may be parallel or otherwise conveniently oriented with respect to each other.
  • the trough 60A and the lead- in 68A have a common axis 70A.
  • the length of the trough 60A and associated lead-in 68A is on the order of 1.59 millimeter.
  • Figure 5 is a plan view of one of the arms 22A.
  • the axes 50A, 70A (respectively through the groove 36A and the trough/lead-in 60A/68A) are offset a predetermined distance 72 in the reference plane RP (the plane of Figure 5).
  • the offset 72 is al least one-half the difference between the diameters of the anticipated largest and smallest fibers to be positioned.
  • offsetting the axes 50A, 70A of the structures 36A, 60A 68A facilitates the centering action of the positioning apparatus 20 by insuring that a fiber, as it is introduced into the apparatus 20, is biased to strike one of the sidewalls 38A, 40A forming the groove 36A (and analogously, the sidewalls 38B, 40B forming the groove 36B). This insures wall contact with the fiber al al least two spaced locations.
  • the presence of the offset 72 necessitates additional manufac ⁇ ng considerations, as will be discussed. It should be note ⁇ that the force resulting from biasing the fiber in the manner just discussed (or the force on the fiber due to gravity) is much smaller in magnitude than the biasing force of the arms which serves to center the fiber on the reference axis.
  • the reference axis R extends centrally and axially through the channel 92.
  • the reference axis R lies on the intersection of the reference plane RP (which contains the conjoined surfaces 34A, 34B) with the plane containing the axes 50A, 50B of the converging grooves 36A, 36B.
  • the registered troughs 60 and lead-ins 68 cooperate to define a guideway 98 ( Figure 2).
  • the axis R' through the guideway 98 lies on the intersection of the plane containing the conjoined surfaces 56A, 56B of the enlargements 54A, 54B (which is the reference plane in the preferred case) with the plane containing the axes 70A, 70B ( Figure 5) of the trough/lead-in 60A/68A, 60L JB.
  • the axes R and R' both lie in the reference plane RP (the plane of the surfaces 34A, 34B, 56A, 56B) although the axes R and R' are laterally offset with respect to each other in this reference plane by a predetermined offset distance 100.
  • the offset distance 100 is typief ly on the order of five (5) micrometers.
  • the inlet end 94 of the fully funnel-like channel 92 (best seen in Figures 4 and 5) is sized to circumscribe and thereby to accommodate a fiber F whose cladding layer L (or outside surface) has the largest expected outer diameter dimension.
  • the outlet end 96 of the channel 92 (best seen in Figure 3) is sized to circumscribe and thereby to accommodate a fiber F whose cladding layer L (or outside surface) has a dimension somewhat smaller than the minimum expected outer diameter dimension of the fiber F.
  • the, largest expected outer diameter dimension is on the order of one hundred twenty nine (129) micrometers while the smallest expected outer diameter dimension is on the order of one hundred twenty one (121) micrometers.
  • each of the troughs 60A, 60B is such that the guideway 98 so ⁇ formed by the registered troughs 60A, 60B is sized to accommodate a fiber F whose cladding layer L has the largest expected outer diameter dimension.
  • the guideway 98 assists in the insertion of a fiber into the positioning apparatus 20 and is advantageous in this regard.
  • the surfaces 34A, 34B on the respective arms 22A, 22B, respectively are, when in a first, closed, position, either in contact with each other or, if desired, within a predetermined close distance to each other.
  • the predetermined close distance is typically on the order of five (5) to twenty-five (25) micrometers.
  • the planar surfaces 34A, 34B on the abutments 32A, 32B of the clips 30A, 30B are not secured to each other and may move to a second, centering, position, as will be described.
  • the planar surfaces 56A, 56B on the respective arms 22A, 22B are secured to each other by any convenient means of attachment, as by fusing or soldering. It should be understood that any other mechanical securing expedient may be used to attach or otherwise hold together the surfaces 56A, 56B to each other.
  • the positioning apparatus 20 further includes, in the preferred instance, a mounting foundation 74 ( Figures 1 and 2).
  • the mounting foundation 74 is provided wilh a planar attachment surface 76 thereon.
  • a step 78 in the mounting foundation 74 serves lo space the attachment surface 76 a predetermined clearance distance 80 from a second surface 82.
  • the opposite major surface, e.g., the surface 28A, of the arm 22A is secured, as by fusing or soldering, to the planar attachment surface 76 on the foundation 74.
  • any alternative mechanical attachment expedient may be used to attach or otherwise hold together the second major surface of the arm to the foundation 74.
  • the second surface 82 of the foundation is shown in the Figures as being generally planar in the preferred case, it should be understood that this surface 82 may take any desired configuration. As will be more fully appreciated herein, so long as the opposite surface 28A of the arm 22A affixed lo the foundation 74 is, al least in the region of the clips 30A, spaced al leasl a predetermined clearance distance 80 from ihe second surface 82 (assuming the surface 82 is parallel to the surface ), the movement of the clip on the arm 22A attached to the loundation (in the drawings, the clip 30A) to be described will not be impeded. 22
  • the clips 30A, 30B disposed at the ends of the arms 22A, 22B, respectively, are supported in a ca ⁇ lilevered fashion from the conjoined enlargements 54A, 54B at the opposite end# of the arms.
  • the arms 22A, 22B are rigid 5 in x-z plane, as del ⁇ ecf by the coordinate axes shown in Figure 1.
  • the? relatively thin dimension of the central region 25A, 25B of ' the base portion 24A, 24B of the arms 22A, 22B axially intermediate the respective abutments 32A, 32B and the enlargements 54 A, 5 B acts as a flexure and permits
  • each arm 22 to flex, springboard fashion, in the directions of the arrows 88 in the y-z plane.
  • a flexure is a spring member that is rigid in one plane and is constrained lo flex in the orthogonal plane. It should further be appreciated that when a clip 30A,
  • Biasing means employing the thinner central region of the base 24 as a flexure (as shown in the Figures 1 to 4) is preferred, because when implemented in a single crystal material using a microfabrication technique precise control of
  • the biasing forces is able to be attained.
  • the bias force on each arm is on the order of five (5) grams.
  • biasing means the bias force must increase with deflection of the arm.
  • the fiber F is inserted into the pos ; " oning apparatus 20 in the direction of the arrow 102 ( Figure 6A).
  • the lead-in portions 68A, 68B ( Figure 1) cooperate to guide the fiber F into the guideway 98 ( Figure 2) defined by the registered troughs 60A, 60B in the enlargements 54A, 54B
  • the end face E of the fiber F enters the channel 92 and is initially displaced through contact with al least one of Ihe sidewalls 38A or 38B, 40A or 40B (or portions of the major surface 26A, 26B, if these are used to define the grooves 36A, 36B, as in Figure 4) on one of the clips 30A, 30B, respectively, lo the extent necessary to place a predetermined point P on an end face E of the fiber F into alignment with the reference axis R. 24
  • the arms 22A, 22B respond to a force in the directions 88A, 88B imposed thereon by the fiber F by moving against the biasing force from the first, closed, position, shown in Figures 7A, 7B, toward a second, centering, position showing in Figures 8A, 8B.
  • the clips 30A, 30B open against the bias force acting in the directions 90A, 90B generated by the flexing of the arms 22A, 22B, to separate the surfaces 34 A, 34B thereon.
  • tabs 48A, 48B are formed on the abutments 32A, 32B these tabs cooperate lo define a passage of uniform width along its axial length that communicates with the outlet of the funnel-like channel.
  • the fiber F passes through and emerges from such a conduit wilh the point P on the end face of the fiber still along the reference axis R.
  • the arms 22' are, similar to the embodiment earlier discussed, articulably movable in cantilevered fashion wilh respect to each other against the bias of the flexure defined by the central portion 25' thereof.
  • the grooves 36' formed in the arms 22' are not converging grooves, but are uniform width grooves.
  • the channel 92' formed by the cooperative association of the arms 22' when superimposed one on the other is a uniform width channel. The maximum dimension of such a channel 92' in the plane perpendicular to the reference R is less than the outside diameter of the smallest anticipated fiber F.
  • FIG. 12 A further modification to the positioning apparatus 20' may be seen from Figure 12. It is first noted that the planar walls 62', 64' of the troughs 60' are parallel, rather than inclined with respect to each ;her. Moreover, the offset 100' between the axes R and R' lies in the vertical plane, that is, in the plane containing the axes 70' of the troughs 60', as opposed to being offset laterally (i.e., in the plane containing the surfaces 56').
  • the lead-in portions 68'A, 68'B are ommitted here but may be provided.
  • a fiber F is inserted into the positioning apparatus 20' and guiued by the passage 98' defined by the registered troughs 60'A, 60'B. Because the axis R' of the passage 98' is vertically offset from the axis R of the channel 92' the surface 26'B of the arm 22'B bounding the passage 98' serves to guide the fiber F toward the inlet end 94' of the channel 92'.
  • the fiber F enters the channel 92' and contacts with the edges of the sidewalls 38'A, 38'B, 40'A and 40'B. Due to the sizing of the grooves 36'A, 36'B the fiber F does not touch the major surface 26'A, 26'B of the arms 22'A, 22'B, 26
  • The, fiber may be chamfered or tapered or a mechanical device may be used lo facilitate insertion of the fiber into the channel 92'.
  • the clips 30'A, 30'B are displaced from the first, closed, position toward a second, centering, position. This movement of the clips 3 ⁇ 'A, 30'B maintains the point P on the end face E of the fiber F on the reference axis R. The end face E of the fiber F thus exits through the outlet end 96' of the channel 92' with the point P precisely aligned on the reference axis R. The fiber F is held in this position by contact with the edges of the sidewalls 38'A, 38'B, 40'A, and 40'B, as indicated by the character LC.
  • Figures 9 to 12 can be further modified, as seen in Figures 13 to 16.
  • the arm 22"B differs from those shown earlier in that no groove is provided therein.
  • the groove is a converging groove, a partially funnel-like channel is defined.
  • the fiber F is guided by contact against the major surface 26"B and held in position on the reference axis R by contact with the major surface 26"B and the edges of the sidewalls 38'A, 38'B, again as indicated by the character LC.
  • Figures 17 and 18 are exploded and assembled perspective views, generally similar to Figures 1 and 2, of another alternate embodiment of a positioning apparatus 20"' in accordance witli the present invention while Figure 19 shows the end view Iftereof.
  • the arms instead of the arms being articulably movable as described earlier, the arms are fixed relative to each other.
  • Each of the arms 22"'A and 22"'B has a converging groove therein and the channel 92"' formed by the cooperative association of the arms 22"' when superimposed one on the other is fully funnel-like in form.
  • the channel 92"' defines a minimum dimension in the plane perpendicular to the reference R that is, near its outlet end, less than the outside diameter of the smallest anticipated fiber F.
  • a fiber F is inserted into the positioning apparatus 20'" and guided through the passage 98'" toward the inlet end 94'" of the channel 92"'.
  • the fiber F enters the funnel-like channel 92"' and is guided by contact with one or more of the sidewalls 38'A, 38'B, 40'A and 40'B and/or major surfaces 26"'A, 26"'B to place the point P of the fiber F on the axis R.
  • the arms 22"' are fixed with respect to each other, the fiber F can only advance within the channel 92"' to the axial location where the outer diameter of the fiber F equals the local dimension of the channel 92"'.
  • the fiber is held in position by a minimum of four point contacts (indicated by the characters PC) between the fiber F and each of the sidewalls 38'A, 38'B, 40'A, and 40'B.
  • the dimension of the channel is such that the fiber is not able to contact the major surface of the arms 22"' when it is held alon,; the reference axis R.
  • Figure 20 illustrates the fiber as the same is held within the channel 92"'.
  • the axial spacing 104 between the end face E of the fiber F and the outlet end 96'" of the channel 92"' varies, dependent upon the outer diameter dimension of the fiber F.
  • the positioning apparatus in accordance with any of the above-described embodiments of ihe invention may be used in a variety of applications which require the precise positioning of a point P on the end face E of a fiber F along a reference axis R. 28
  • each positioning apparatus 20-1 , 20-2 (corresponding to the embodiment shown in Figures 1 and 2) are arranged to define a fiber-to-fiber connector generally indicated by the reference character 120.
  • the apparatus 20-1 , 20-2 are confrontationally disposed wilh respect to the other so thai the outlet ends 96 of the respective channels 92 therein are spaced a predetermined distance 122 with the respective reference axes R therethrough being collinear.
  • the foundation 74 is extended in an axial direction and each axial end thereof is provided with a planar attachment surface 76.
  • Each positioning apparatus 20-1 , 20-2 is mounted to its respective attachment surface .
  • the fibers F- ⁇ and F-2 to be connected are inserted into the lead-ins 68 of the respective positioning apparatus 20-1 , 20-2.
  • Each positioning apparatus 20-1 , 20-2 acting in the manner described above, serves to place the point P on the end face E , of the respective fiber F-1 or F-2 along the collinearly disposed axes R'.
  • the fibers F- 1 , F-2 are inserted in to the respective apparatus 20-1 , 20-2 until the ' end faces E, E' abut.
  • the ends E of the fibers F-1 , F-2 are secured due to the above- described holding action of the positioning apparatus.
  • an suitable index matching adhesive such as an ultraviolet curing adhesive such that manufactured and sold by Electro-Lite Corporation, Danbury, Connecticut as number 82001 ELC4480, may be used.
  • the fiber-to-fiber conneclor may be implemented using any of the above-discussed alternative embodiments of the positioning apparatus.
  • the confronting ends of the positioning apparatus 20"'-l , 20"'-2 are preferably abutted and secured, or the pair of positioning apparatus formed integrally with each other.
  • the spacing 122 between the end faces E of the fibers F-1 , F-2 is, in this embodiment, defined by the sum of the distances 104-1 , 104-2.
  • the spacing 122 is filled with an index matching material, such as the adhesive defined above.
  • an access port 124 is provided to permit the introduction of the irsdex matching material into the region between the confronting end face of the fibers F-1 , F-2.
  • the jacket J ( Figure 29) of the fiber F is stripped in its entirety a predeterm _ ⁇ ed distance from the free end thereof.
  • the exposed portion of the fiber is cleaned with alcohol.
  • the fiber is cleaved to form the end face E. If desired the end face E may be ground into a convex shape lo yield a point or be lensed.
  • the fiber-to-fiber connector 120 may be disposed in a suitable housing 130 (figure 25).
  • the preferred form of the housing 130 is generally similar to that disclosed in United States Patenl 4,784,456 (Smith), assigned lo the assignee of the present invention. This patent is hereby incorporated by reference herein.
  • the housing 130 includes a base 132 and a cover 134.
  • the base 132 is, in all cases, provided wilh a recess 136 that is sized lo closely receive the connector 120.
  • the cover 134 must be provided with a corresponding recess 138 located so as to permit the articulating motion of the arms of positioning apparatus used to form the connector.
  • the connector ⁇ 20 is realized using the form of the positioning apparatus shown in Figures 23 and 2 -. , the recess 138 need not be provided.
  • Such a housing 130 is shown in Figure 28. 30
  • the cover 134 is segmented into three sections, 140A, 140B, 140C, each which is hinged to the base 132.
  • the base 132 has, adjacent to each end of the recess 136, V-shaped grooved regions 142/ ⁇ , 142B.
  • the top end sections 140A, 140B each contain respective generally tapered lands 143 A, 143B. Each of the lands has serrations 145A, 145B respectively thereon.
  • a connector is inserted in the recess 136 of the housing 130. It is t ⁇ ere held in place by friction but may be otherwise secured if desired. The central section HOC of the cover may then be closed, if desired. An optical fiber having a predetermined length of its jacket J stripped and cleaned, is inserted through one of the V-shaped grooved regions 142A,
  • the housing 130 is preferably formed by injection molding.
  • the housing 130 may be implemented using a mass 160 of index matching material, such as that identified above.
  • the mass 160 extends over both the connector 120 (to embed the same therein) and some predetermined portion of the jackets J of the fibers F-1 , F-2. -o-O-o-
  • the reference axis R on which the point P of the fiber F is positioned may itself extend collinearly with the axis X of any of a variety of devices. Accordingly, a positioning apparatus 20 may be used to accurately position the point P on the end face E of the fiber F with respect to the axis X of a particular device 170.
  • Figures 30, 31 and Figures 32, 33 illustrate several examples of the use of a positioning apparatus 20 to locate a fiber F along an axis X of a device 170.
  • the device 170 may, for example, be realized by any active optical component, such as a solid state laser, a photodiode, a light emitting diode, whether these devices are edge active devices or surface active devices.
  • the reference character 20 is used lo indicate the positioning apparatus, it should be understood that any one of the embodiments of the positioning apparatus heretofore described may used.
  • the foundation 74 is axially extended to define a pedestal 174 at the axial "nd thereof.
  • the upper surface 176 of the pedestal 174 defines a planar attachment surface.
  • the surface 176 is spaced a predetermined distance above the attachment surface 76 or otherwise located such that when the active optical component 170 is mounted the surface 176 the axis X of the device 170 and the reference axis R are collinear. With the axes R and X collinear, the positioning of the point P on the fiber F along the axis R will automatically position that point P in the same relationship wilh the axis X.
  • the device 170 must be accurately mounted on Ihe surface 176 so that its axis X is collinearly aligned wilh ihe axis R. 32
  • the surface 176 may be provided with a layer of solder layer, such as a gold/tin solder.
  • the device 170 may have a corresponding layer of the same material.
  • the device 170 is positioned on the surface 176 using a suitable micr ⁇ positioning apparatus, such as a vacuum probe. The device is aligned to the edge, heated above the melting point of the solder and cooled, so that the solder forms a bond.
  • the acti ⁇ je surface of the device 170 is secured lo the front surface 178 of the pedestal 174. Attaching the device to the front surface 178 is believed to provide sufficient bonding area to secure the device 170 to the positioning apparatus 20. ' The surface 176 of the pedestal 174 is relieved to avoid obstruction between the active region of the device 170 and the end face E of the fiber F.
  • the positioning apparatus in accordance with any one of the embodiments heretofore described may be configured to accurately position a lens, such as a ball or a rod lens L, with respect to the axis of the device 170 (whether the same is an edge active or a surface active device).
  • the positioning apparatus would be modified to provide a seat 3 I S in the clips 30 thereof sized to accept the lens L.
  • a positioning apparatus 20 may be understood from the following discussion take , in connection with Figures 34 to 40. Although the discussion is cast in terms of the manufacture of a fiber-lo-fiber connector 120 using the preferred embodiment of the positioning device 20, as shown in Figure 22, the teachings are readily extendable to the manufacture of any of the embodiments of the positioning apparatus heretofore described, including their use in the various other applications previously set forth.
  • a silicon wafer 200 having an appropriate predetermined crystallographic orientation is the starting point for fabrication of the arms 22 of a positioning apparatus 20 in accordance with the present invention. It should be understood that other single crystalline substrate materials, such as germanium, may be used provided appropriate alternative etchants a_ ⁇ d materials compatible with the selected alternative substrate are used.
  • the wafer 200 is polished on at least one surface. Suitable silicon wafers are available from SEH America, Inc., a subsidiary of Shin-Etsu Handotai Co. Ltd., Tokyo, Japan, located at Sparta, New Jersey. It should be understood that the wafer 200 can be of the "p-type", "n-type” or intrinsic silicon.
  • the substrate material is preferably ( 100) surface silicon because this material can be eiched by anisotropic etchants which readily act upon the (100) crystallographic plane but substantially do not etch the ( 1 1 1 ) plane.
  • the preferred truncated V-shaped grooves 36A, 36B, the troughs 60A, 60B, the lead-ins 68A, 68B and the central region 25A, 25B of the arn 22A, 22B between the abutments 32A, 32B and the enlargements 54A, 54B are easily formed.
  • the width and depth of such featur s are dependent upon the preselected width of the opening in the photolithographic mask being used and the time during which the elchants are permitted to act.
  • Etchants operate on 100 surface silicon in an essentially self- limiting manner which property is useful in forming a full V-groove.
  • One of skill in the art will recognize that if other cross-section configurations are required, other predetermined crystallographic orientations of the silicon may be used. For example, if square cross-section features are desired, (110) surfaces silicon wafers can be used. Other cross sectional configurations for the features are, however, significantly more expensive and, as will be seen later, would require a more complicated configuration to obtain the fiber centering action equivalent to thai inherent in a V-groove.
  • Figure 34 is a plan view of the wafer 200.
  • the wafer 200 has peripheral flats 201 and 202, as specified by the SEMI Standard.
  • the flats 201 , 202 primarily indicate orientation of the crystallographic structure of the silicon and are' also used for wafer identification and mask alignment.
  • the longer flat 201 indicates the direction of crystallographic plane (1 10).
  • the shorter flat 202 is placed a predetermined angular amount on the periphery of the wafer with respect to the flat 201 , the magnitude of the angle depending upon the doping of the crystal.
  • the peripheral regions 203 of the wafer 200 when prepared, carry alignment grooves, while the central region 204 of the wafer 200 has the structural features of the arm or foundation, as fhe case may be, of the positioning apparatus formed thereon.
  • Figure 35 shows a mask 210 with a patterns 212 of orthogonal alignment grooves thereon.
  • the grooves in each pattern 212 are graduated in size lo accommodate various sized (diameter) quartz alignment fibers.
  • the grooves 212 have a V-shaped cross section to accept fibers ranging in width from about 0.004825 inches (0.123 mm) to 0.005000 inches (0.127 mm) in 0.039370 inch (0.1 mm) steps, five grooves 212 having been illustrated.
  • the groove width (at the open top of the groove) is larger than the diameter of the fiber so that the center of the fiber is substantially coplanar with the surface of the wafer when the fiber is disposed in its associated groove. Accordingly, for a 0.123 mm fiber, a groove 0.1506 mm is provided.
  • the open top dimension of the groove is 0.1518 mm.
  • the open top dimension of the groove is 0.1531 mm; for a 0.126 mm fiber the open top dimension of the groove is 0.1543 mm.; and for a 0.127 mm fiber, the open top dimension of the groove is 0.1555 mm.
  • a central area 214 of the mask 210 has provided thereon a repetitive pattern 220 (one of which is shown in Figure 36) containing to a predetermined number of structural features (i.e., arms or foundations) of the positioning apparatus 20 being formed. Since the typical wafer 200 is about 3.9381 inches (101.028 mm) in diameter and a typical connector 120 measures about t! ,r ee hundred fifty (350) micrometers at the widest location and is about two thousand eight hundred (2800) micrometers in length, the siructural features for approximately one thousand ( 1000) connectors 120 may be formed from the central region 204 of the wafer 200.
  • Figure 36 is an enlarged view of a portion 220 of the pattern provided on the central region 214 of the mask 210.
  • the pattern illustrated is that used to form a plurality of conjoined arms 22 used in a connector 120 ( Figure 22).
  • the pattern 220 is formed on the surface of the central region 214 of the mask 210 using a well-known step and repeat process to cover the entire area.
  • the repetitive pattern 220 shown in Figure 36 is comprised of ⁇ plurality of columns 224 which are defined between an array of adjacent parallel scribe lines 226 and a first and a second separation line 227 A and 227B.
  • Each column 224 contains ten (10) discrete zones 228 A through 228E that are symmetrical withm the column 224 about a cutting line 230.
  • Seen between two next adjacent scribe lines 226 is the configuration of two arms 22 joined front end to front end. Seen between three next adjacent scribe lines 226 is the configuration of two arms 22 joined lengthwise side to side.
  • the zone 228A corresponds to features defining the region of the lead-in 68 A of an arm 22A.
  • the zone 228B corresponds to features defining the region of the trough 60A of the arm 22A.
  • zone 228C corresponds to the central portion 25A of the arm 22A, while the zone 228D corresponds to features defining the region o ⁇ the converging groove 36A on the arm 22A.
  • the axis 50A of the converging groove 36A is offset from the axis 70A of the trough 60A by the offset distance 100.
  • the zone 228E corresponds to features defining the region of the tabs 48A of an arm 22A. Note that in the mask illustrated in Figure 36 the position of the offset 100 on one side of the cutting line 230 is reversed from the position of the offset 100 on the opposite side of the cutting line, although this arrangement is not necessarily required.
  • the repetitive pattern for a mask of the arm 22B will be similar to that shown in Figure 36 except that the direction of the offset distances 100 for the arm 22B will be the mirror image of the pattern for Ihe arm 22A. As will be come clearer herein, this mirror image relationship between the offsets is necessary so that so J,hat features on the resulting arms 22A, 22B will register with each other when one is inverted and superimposed on the other. Of course if the offset 100 is eliminated, masks for the arms 22A and 22B will be identical.
  • the cross-hatched areas shown in Figure 36 preferably correspond to those areas of the central region of the wafer 200 that will be protected by a layer of resist material (as will be described) while the areas shown without hatching will be left unprotected during subsequent etching steps. A negative resist is employed but it should be apparen' that the location of the hatched and clear areas of Figure 36 may be reversed if desired. This would alter somewhat subsequent steps, but in a manner known to those in the art.
  • Figures 37A through 37E illustrate the process steps whereby a wafer 200 of crystalline silicon may be formed into an array of arms 22A corresponding to the array shown on the mask of Figures 35 and 36.
  • the wafer 200 is preliminarily covered with a layer 232 of a material that acts in a manner similar to a mask.
  • Silicon nitride (SJ3N 4 ) is preferred, and is surfaced onto the polished operative surface 200S of the silicon wafer 200 by thermally growing the silicon nitride layer in an oxygen atmosphere at elevated temperature (circa seven hundred fifty (750) degrees Celsius), as is known.
  • silicon nitride is used because available etchants that attack silicon will also attack known photoresists but will not affect silicon nitride.
  • a suitable nitride layer is grown onto the wafer by CVD Systems and Services, Incorporated, Quakertown, Pennsylvania.
  • the layer of silicon nitride 232 is then covered with a photoresist 234.
  • Preferred " s a positive resist, such as the mixture of 2-ethoxyelhyI acetate, N-butyl acetate and xylene sold by Shipley Company, Incorporated of Newton,
  • the resist is spun onto the surface of the silica nitride in accordance with instructions set forth in he Shipley Microelectronic Products Brochure (1984) using standard apparatus such as that available from Headway Research Incorporated of Garland, Texas under model number ECR485.
  • the mask 210 ⁇ is mounted atop the wafer 200 and is aligned wilh respect to the flats 201, 202 of the wafer 200 using alignment bars 235.
  • the alignment grooves 212 are precisely positioned with respect to the flats on the wafer through the use of alignment bars 213 on the mask.
  • the wafer 200 is exposed to ultraviolet light through the mask 210 and subsequently developed.
  • the pattern of the mask 210 is etched into the silica layer 232.
  • Phosphoric acid (H3PO4) is preferred. This step results in the arrangement shown in Figure 37C.
  • process variables such as, for example, concentration, time and temperature are all adjusted appropriately to optimize results in all of the wet processing steps described.
  • a second, differential, etching step is performed to etch the silicon to form the features of the arms 22A.
  • an anisotropic etchant such as ethylene diamine (“ED") pyrocatechol (“P”) and water.
  • ED ethylene diamine
  • P pyrocatechol
  • KOH potassium hydroxide
  • This etching produces the structural feature in the surface of the silicon illustrated schematically in Figure 37D by reference character 236.
  • the depth of the feature 236 is controlled by controlling the etching lime, as is well known.
  • differential etching is self-limiting for the inside angles of the structure, if left to proceed.
  • the silicon nitride layer 232 is then removed by etching with phosphoric acid and a layer of silica, i.e., silicon dioxide, is grown on the surface.
  • a layer of silica i.e., silicon dioxide
  • resist is deposited on the surface of the wafer and is imaged through a mask, as shown Figure 38. This results in a layer 238 of hardened resist being formed on those predetermined portions of the wafer that are to be bonded (corresponding to zones 228C through 228E and to troughs 60 (see Figure 36)).
  • the silicon layer is then etched from areas that are not to be bonded (See, Fgiure 37E) using hydrofluoric acid (HF).
  • HF hydrofluoric acid
  • the resist layer 238 is stripped using acetone, leaving a finished wafer ready for bonding.
  • the mask for the arms 22B is not identical with the mask used to form the arms 22A. Accordingly, a second wafer having an array of arms 22B thereon must be prepared in accordance with the method steps illustrated in Figure 37.
  • the finished second wafer (not specifically illustrated but hereinafter referred to by character 200') is similar in all respects except in location of the offset 100.
  • a third wafer 200" is prepared using a foundation mask, a portion of which is shown in Figure 39.
  • Figure 39 is an enlarged view of a portion of the pattern 220' provided on the central region of the foundation mask (analagous to the pattern of the arm mask shown in Figure 36).
  • the repetitive pattern 220' is comprised of a plurality of columns 244 which are defined between an array of adjacent parallel scribe lines 246 and a first and a second separation line 248A and 248B.
  • Each column 244 contains four (4) discrete zones 250 that are symmetrical v?ilhin the column 244 about a center line 252.
  • the zones 250A de ⁇ rte mounting surface 76 on a foundation 74.
  • the zones 250 ⁇ correspond to the surfaces 82 provided on the foundation.
  • the wafer 200" containing the foundations 74 is exposed in a manner analagous to that shown in Figure 37, wilh the exception that the exception that the solder mask exposure is not carried out. However, the layer of silica is removed from the surface of the wafer 200".
  • the final assembly of the connector 120 may be made as is shown in Figure 40.
  • the wafer 200' is placed on top of the wafer 200.
  • the registration of the features on the wafer 200' to those on the wafer 200 is effected using at least two and preferably four lengths of a stripped optical fiber and the corresponding appropriate one of the alignment grooves, in each array 212 of grooves.
  • the diameter of each length of the optical fiber is measured by micrometer, accurate to plus or minus 0.5 micrometers.
  • Each of the fibers is placed in groove in the groove array 212 that most closely corresponds lo the measured diameter. -
  • Each alignment fiber thus sits in the selected alignment groove such that the axis of the alignment fiber lies in the plane of the surface of the wafer 200 with the remaining portion of each fiber protrudes above that surface.
  • the wafer 200' is inverted and placed atop the wafer 200 with the corresponding grooves in the wafer 200' rect ng the protruding portions of the alignment fibers thereby to precisely align the pattern of the two wafers. Since 5 the alignment grooves on each wafer are formed simultaneously with the formation of the features on the wafer, and since the mask for each wafer is formed ontically one from the other, precise alignment between the wafers is achieved. It is noted in Figures 40A and 40B only one of the fibers 254 and l O grooves 121 is shown, for clarity of illustra' » on.
  • the resulting bonded structure is inverted and the exterior surface 256' of the wafer 200' is mounted atop the
  • the resultant three wafer bonded stack shown in Figure 40D may then be cuL Only the top two wafers 200, 200' of the bonded stack (containing the arms 22-1 B, 22-2B and the arms 22-1 A, 22-2A, respectively, Figure 22) are first cut along the lines in the wafers corresponding to the cutting lines 230, 230' on the arm masks ( Figure 36). This cut is made using a blade that is on the order of 0.003 inches to create the distance 122 in Figure 22.
  • the bonded stack is thereafter cut, using a blade that is 0.015 inches thick, along the lines in the wafers corresponding to the separation lines 227A, 227B on the wafer 200, the separation lines 227A', 227B' on the wafer 200', and the separation lines 248A, 248B on the wafer 200", as well along the scribe lines 226, 226' and 246 (on the respective wafers 200, 200' and 200") all of which are registered with each other, thereby to yield from the bonded stack about one thousand of the fiber- to- fiber connectors 120.
  • Figure 42 in addition lo the various embodiments of the two-armed configurations for the positioning apparatus of the present invention previously disclosed, it lies within the contemplation of this invention for a positioning appaiatus to exhibit more than two arms 22.
  • Figures 42A lo 42C illustrate a positioning apparatus having three arms 22A, 22B and 22C
  • Figures 42D through 42F illustrate a positioning apparatus having four arms 22 ⁇ , 22B, 22C and 22D.
  • the extension to even greater number of arms would be readily apparent to those skilled in the art. 5
  • each the arms are configured similar to the form of the arms discussed above.
  • the arms may, if desired carry a groove, although il should be understood that such is not required.
  • the arms are configured
  • the arms are configured in a generally planar bar form.
  • the four arms may be formed by sawing the upper and lower arms
  • I f (indicated by the characters 22A, 22B in Figures 1 to 4) along a cut line extending perpendicular to the major suraces 26 and 28 of each of the arms.
  • the arms are shown in Figures 42A 0 through 42F as angularly juxtaposed in a surrounding relationship to the channel 92 defined their cooperative association. Similar lo the situation described heretofore the resiliency of the arms defines the biasing means which urge the arms toward the closed position. However, it should be 25 understood that the biasing means may be otherewise defined, so long as the force on each arm passes through the reference axis and the sum of forces on the arms when they are in the centering position is substantially equal to zero. Whatever form of biasing means is selected the bias force must increase 3t with deflection of the arm.
  • the arms act against the fiber F inserted into the channel along the various lines of contact LC illustrated in Figure 42 to maintain the predetermined point on the fiber on the reference axis R. It should be understood that such modifications as herein preented and any others are to be construed as lying within the contemplation of the present invention, as defined by the appended claims.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
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Abstract

Un élément opto-électronique comprend un dispositif opto-électronique (20) du type qui est actif au bord ou du type qui est actif à la surface, ledit dispositif étant monté sur un support. Une fibre (F) est mise en place par un dispositif (20) de positionnement.An opto-electronic element comprises an opto-electronic device (20) of the type which is active at the edge or of the type which is active on the surface, said device being mounted on a support. A fiber (F) is put in place by a positioning device (20).

Description

TITLE
OPTO-ELECTRONIC COMPONENT HAVING A POSITIONED
OPTICAL FIBER ASSOCIATED THEREWITH
CROSS REFERENCE TO RELATED APPLICATION
Subject matter disclosed herein is disclosed and claimed in copending application Serial Number 07/388,546 . filed contemporaneously herewith, titled "Apparatus For Positioning The Center Of An Optical Fiber Along a Predetermined Reference Axis".
BACKGROUND OF THE INVENTION
Field Of The Invention The present invention relates to an opto-electronic component having a positioning apparatus for positioning the center of an optical fiber along a predetermined reference axis of an opto-electronic device independently of variations in the outside diameter of the fiber.
Description Of The Prior Art Devices are known for positioning an optical fiber so that the axis of the fiber is positioned with respect tc a reference axis. A typical expedient used in such devices is a generally V-shaped groove that is formed in a substrate material and which serves as a cradle to accept the fiber being positioned. Representative of such devices is that shown in United States Patent 4,756,591 (Fischer et al.), wherein a V-groove is formed in a silicon substrate and an elastomeric member is biased against the fiber to hold it in the groove. The groove may be stepped to provide a deeper groove segment to hold the jacket of the fiber within the device.
.. f United States Patent 4,756,591 (Sheem) discloses a grooved silicon substrate having a pair of intersecting V- grooves therein. A fiber to be positioned is disposed in one of the grooves while a shim is disposed in the other of the grooves. The shim may take the form of a tapered or an eccentric fiber, which when respectively slid or rotated under the first fiber serves lo lift the same lo bring the* axis thereof into alignment with a reference axis. A cover may be positioned above the substrate to assist in clamping the first fiber into position.
United States Patent 4,802,727 (Stanley) also discloses a positioning arrangement for optical components and waveguides which utilizes a V-grooved struclure. United States Patent 4,826,272 (Pimpinella et al.) and United States Patent 4,830,450 (Connell et al.) discloses arrangements for positioning an optical fiber that utilize members having frusloconical apertures therethrough.
It is believed that single crystalline silicon is the material of choice of the devices above mentioned because of the proclivity of crystalline silicon to be etched along precise crystallographic planes, thus forming precise grooves or structural features by photolithographic microfabrication techniques. Etchants exist that act upon a selected crystallographic plane to a differential degree than upon an adjacent plane, permitting the needed precise control. V- grooves, in particular, can be etched to a controlled width and truncated depth. Under some conditions V-grooves may be etched in a self-limiting operation. The photolithographic microfabrication process is generally described by Brodie and Muray, "The Physics of Microfabrication", Plenum Publishing, New York (1982).
Optical fibers include an inner core having a predetermined index of refraction surrounded by a cladding layer of a lower index. The inner core is the medium in which the optical energy is guided, while the cladding layer defines the index boundary with the core. The outer diameter of the fiber may vary in dimension about a predetermined nominal dimension. Il has been seen, ff example, that two nominally identical fibers from the same manufacturer may vary in outside diametrical dimension by as much as plus or minus four (4) micrometers. This fiber to fiber variation in outer diameter makes difficult the accurate positioning of the axis of the core of a fiber with respect to a predetermined reference axis.
In view of the foregoing it is believed advantageous to make use of the ability of microfabrication techniques to form accurate structurer channels and/or surfaces in a crystalline material to construct a positioning apparatus that will accurately position the center of the fiber, or of any other elongated generally cylindrical member having small dimensions (such as capillary tubing), with respect to a predetermined reference axis. Moreover, it is believed advantageous to provide a positioning apparatus that consistently aligns the predetermined point on the fiber or other cylindrical member with the reference axis without requiring great technical skill, expensive apparatus, and extensive alignment procedures. SUMMARY OF THE INVENTION
The present invention relates to a relates to an opto- electronic component having a positioning apparatus for positioning the center of an optical fiber along a predetermined reference axis of an opto-electronic device independently of variations in the outside diameter of the fiber. The opto¬ electronic device can take the form of a solid state laser or a solid state light responsive diode such as a photodiode. The opto-electronic device can be an edge active or a surface active device. The optical fiber can be a single-mode or a multi-mode fiber.
The positi ning apparatus includes a first and a second arm, each of which has at least a first and a second sidewall that cooperate to define a groove therein. The groove in each arm is preferably a converging groove so that when the arms are arranged in superimposed relationship the converging grooves cooperate to define a funnel-like channel over at least a predetermined portion of its length. The channel has an inlet end and an outfet end and a reference axis extending therethrough. A fiber introduced into the inlet end of the channel with its axis spaced from the reference axis is displacable by contact with at least one of the sidewalls on one of the arms to place a predetermined point on an end face of the member into alignment with the reference axis where it is there held by contact with the first and second arms. To guide the fiber toward* the inlet end of the channel each of the first and the second arms includes a trough therein, each trough being disposed on an arm a predetermined distance behind the groove in that arm, so that in the closed position the troughs cooperate to define a guideway. The arms having the converging grooves therein may, as is preferred, be movable from a first, closed, position to a second, centering, position. The superimposed arms are, in this instance, mounted cantilevered fashion, to a foundation. Means is provided for biasing each of the arms with a substantially equal and oppositely directed biasing force toward the first position. In the preferred implementation the biasing means comprises a reduced thickness portion in each of the first and the second arms, the reduced thickness portion defining a flexure in each arm which, when each arm is deflected by contact with the cylindrical member, generates a force on each arm to bias each arm toward the closed position.
It should be understood that so long as the arms are movable and biased toward the closed position, it is not required that the grooves formed therein are converging grooves. Accordingly, other positioning apparatus in which the arms are movable but in which the grooves in each of the arms have a form other than a converging groove are to be construed as lying within the contemplation of the invention. Succinctly stated, the present invention encompasses any positioning apparatus having arms that are movable whether the groove in each arm take the form of a converging groove or £ groove of an alternate Torm. Alternately, the present invention also encompasses any positioning apparatus in which the groove in each arm is converging in form, whether the arms are movable or fixed with respect to each other.
In whatever embodiment realized, it is preferred that the positioning apparatus be fabricated from a crystalline material, such as single crystal silicon, using microfabrication techniques. Each structural element of the positioning apparatus (viz., each of the arms arήd each foundation) is fabricated in mass on a wafer of silicon. The finished wafer are aligned, superimposed, and bonded, and each of the resulting positioning apparatus
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from the following detailed description thereof, taken in connection with the accompanying drawings, which form a part of this application, and in which:
Figure 1 is a perspective, exploded view of a positioning apparatus in accordance with the preferred embodiment of the present invention for positioning the center point on the end face of an optical fiber with respect to a predetermined reference axis;
Figure 2 is a perspective view of the positioning apparatus of Figure 1 in the fully assembled condition;
Figure 3 is a front elevation view of the assembled positioning apparatus of Figures 1 and 2, taken along view lines 3-3 in Figure 2;
Figure 4 is a sectional view, in elevation, of the assembled positioning apparatus of Figure 2, taken along section lines 4-4 in that Figure illustrating the truncated V-groove therein;
Figure 4A is a view generally similar to Figure 4 in which a full V-groove is formed in the positioning apparatus while Figure 4B is a view generally similar to Figure 4 in which both a full V-groove and a truncated V-groove are formed;
Figure 5 is a plan view one of the arms of the positioning apparatus of Figure 1 illustr iting the relationships of the axes of the groove and the guideway therein; Figures 6A and 6B, 7A and 7B, and 8A and 8B are diagrammatic elevational and end views of the action of the clips disposed on the arms of the positioning apparatus shown in Figures 1 and 2 in response to the introduction of a fiber thereinto;
Figures 9 and 10 are exploded and assembled perspective views, generally similar to Figures 1 and 2, of another alternate embodiment of a positioning device in accordance with the present invention in hich the arms have nonconverging grooves therein and in which the arms are articulably movable with respect to each other along one axis only;
Figures 11 are 12 are sectional views taken along section lines 1 1-1 1 and 12-12 in Figure 10;
Figures 13 and 14 are exploded and assembled perspective views, generally similar to Figures 1 and 2, of another alternate embodiment of a positioning device in accordance with the present invention in which only one of the arms has a nonconverging groove therein and in which both of the arms are articulably movable with respect to each other;
Figures 15 are 16 are sectional views taken along section lines 15-15 and 16-16 in Figure 14;
Figures 17 and 18 are exploded and assembled perspective views, generally similar lo Figures 1 and 2, of an alternate embodiment of a positioning device in accordance with the present invention in which the arms have converging grooves therein and in which the arms are fixed with respect to each olher;
Figure 19 is an end view taken along view lines 19-19 in Figure 18; Figure 20 is a side sectional view, taken along view lines 20-20 in Figure 18, illustrating the position of the fiber within the channel of the a positioning apparatus in accordance with the alternate embodiment of the invention shown therein;
Figure 21 is an exploded isometric view of a pair of positioning apparatus as shown in Figure 1 used to form a fiber-to-fiber connector in accordance with the present invention while Figure 22 is an isometric view of the fully assembled connector of Figure 21 ;
Figures 23 and 24 are, respectively, a top view in section and a side elevation section view of a pair of positioning apparatus in accordance the embodiment of the invention as shown in Figure 17 used to form a fiber-to-fiber connector in accordance with the present invention;
Figures 25 and 26 are isometric views of a housing used for the fiber-to-fiber connector shown in Figures 21 and 22 in the open and in the partially closed positions, respectively, while Figure 27 is a section view of the housing of Figure 25 in the fully closed position taken along section lines 27-27 of Figure 26;
Figure 28 is a section view generally similar to Figure 27 of a housing used for the fiber-to-fiber connector shown in Figure 24;
Figure 29 is a isometric view of an alternate housing for a fiber-to-fiber connector formed of a pair of positioning apparatus;
Figures 30 and 31 are isometric exploded and assembled views, respectively, illustrating the use of a positioning 10
apparatus in accordance with the present invention to position an optical fiber wϊtrf respect to the axis of an edge emitting active device, in which the device is surface mounted;
Figure 31 A is a side elevational view generally similar to
/ Figure 31 showing a positioning apparatus in accordance with the present invention positioning a lens with respect to an opto-electronic component;
Figures 32 and 33 tire isometric exploded and assembled views, respectively, generally similar to Figures 30 and 31 , illustrating the use of a positioning apparatus in in accordance with the present invention to position an optical fiber with respect to the axis of a device having active surface device, in which the device is edge mounted;
Figure 34 is a perspective view of a wafer used used to fabricate a plurality of arms or foundations used in a positioning apparatus, in accordance with the present invention;
Figure 35 is a perspective view of a mask used in the photolithographic process forming a plurality of arms or foundations for a positioning apparatus in accordance with the present invention;
Figure 36 is an enlarged view of a portion of the mask used for creating a plurality of arms on the wafer 34;
Figures 37A through 37E are schematic representations of the process steps effected during fabricalion of the wafer;
Figure 38 is is an enlarged view of a portion of the mask used for creating solder masks on the wafer; Figure 39 is an enlarged view of a portion of the mask used for creating foundations on the wafer;
Figures 40A through 40D are schematic representations of the steps used to form a plurality of fiber-lo-fiber connectors from superimposed wafers having the arms and foundations thereon;
Figure 41 is a definitional drawing illustrating the characteristics of a converging groove as that term is used in this application; and
Figures 42A through 42F are end views showing alternate arrangements of movable arms each holding a cylindrical member along at least three contact points in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Throughout the following detailed description similar reference numerals refer to similar elements in all Figures of the drawings.
With reference to Figures 1 and 2 a positioning apparatus generally by reference character 20 in accordance with the present invention is shown in an exploded and in a fully assembled condition. As will be developed herein, in the preferred instance the positioning apparatus 20 is microfabricaled from single crystal silicon or another differentially etchable single crystal material. These materials are preferred because they permit the accurate formation of the structural features of the apparatus 20 using the process of differential etching. The positioning apparatus 20 is useful in accurately positioning a predetermined point on the end face of a cylindrical member, typically a point on the central axis of the member, along a rejje en e axis. Typically this reference axis is itself collinearly aligned with respect to another axis, as an operative axis of a device operably associable with the cylindrical member. Throughout this application the description of the cylindrical member is cast in terms of an optical fiber, but it is to be understood thai the present invention may be effectively utilized with any other member having the form of small diameter cylindrical object. By way of example and not limitalion, the positioning apparatus invention may be used to position a point on the end face of a length of microlubing or capillajy tubing. By small diameter it is generally meant less than 0,04 inch (one (1) millimeter), but usually less than 0.020 inch. Moreover, it should be further understood that the term cylindrical is not to be strictly limited to an object having a completely circular outer configuration, but would apply to any object whose outer contour is symmetrical to its central axis. Thus, again by way of further example and not limitation, the positioning apparatus of the present invention may be used to position a point on the end face of a polygonal shaped member or an elliptical member.
As noted, the cylindrical member preferably takes the form of an optical fiber. The positioning apparatus of the present invention is particularly adapted to place a predetermined point P on the end face E of an optical fiber F along a predetermined refererice axis R. In practice the point P is the geometric center and Ifes on the axis A of the core C (Figures 6A and 6B) of the fiber F. The core C is itself surrounded by an outer cladding layer L. A jacket J is provided about the cladding layer L but is stripped from the fiber F prior to the insertion of the fiber into the positioning apparatus 20. The jacket may comprise more than one layer. As discussed previously, the dimension of the outer diameter D of the cladding layer L of the fiber F may vary from fiber to fiber. Typically this diametrical variation from fiber to fiber is on the order of three (3) micrometers. This situation makes difficult the positioning of the point P along the reference axis R using the positioning devices of the prior art. The fiber may be a single-mode or a multi-mode fiber. As will be seen from the following the positioning capability of the positioning apparatus 20 is especially adaplec for positioning the point P of a single mode fiber within the precise tolerances required to effectively couple light emanating from the single mode fiber into another fiber or lo position the fiber with respect to an optical device.
With reference to Figures 1 and 2 it is seen that the positioning apparatus 20 includes a first and a second arm 22A, 22B, respectively. Preferably, each of the arms 22A, 22B is identically formed in manner to be discussed, so the structural details of only one of the arms, e. g., the arm 22A, will be discussed. It should be apparent, however, that each structural detail of the arm 22A finds a counterpart in the other arm 22B. Accordingly, corresponding reference numerals with the appropriate alphabet suffix will denote corresponding structural details on lb ; arm 22B. If the arms are not substantially identical (as, for example, in the embodiments of Figures 13 through 16 and Figure 42) adjustments must be made to provide the requisite biasing forces to maintain the point P on the reference axis R
The arm 22A incudes a base portion 24A having a first major surface 26A and a second, opposed, major surface 28A. The base portion 24A extends along the full length of the arm 22A and the dimension of the central region 25A of the base portic n 24A defines the basic dimension of the arm 22A. A clip generally indicated by the reference character 30A is defined at a first end of the arm 22A. The clip 30A is formed in a relatively thicker abutment portion 32A that lies on the first surface 26A of the arm 22A. The abutment 32A has a planar surface 34A thereon that preferably lies parallel to the first major surface 26A. To provide some feeling for the physical dimensions involved, the arm 22A has an overall length dimension on the order of twenty eight hundred (2800) micrometers and a width on the order of three hundred fifty (350) micrometers. In the central region 25A the arm 22A has a thickness dimension on the order of fifty (50) micrometers, while the remaining portion of the arm 22A has a thickness dimension on the order of one hundred twenty five (125) micrometers.
As may be better seen with reference to Figures 3 and 4 a generally converging V-shaped groove 36A is defined in the abutment 32A of the clip 30A by generally planar first and second sidewalls 38A, 40A, respectively, and the forward end region of the first surface 26A of the base 24A. The sidewall 38A has an upper edge 39A (Figure 1) thereon while the sidewall 40A has an upper edge 41 A thereon. It should be understood that the term "planar" is meant to encompass a surface formed in a single crystal material by etching in which microscopic steps are of necessity produced owing to the lattice structure of the crystal.
With reference ι$pw to the definitional drawing of Figure 41 , the meaning of tire term "converging" when applied to a groove (using the reference characters of Figures 1 and 2) may be made more clear. As used herein, a "converging" groove is a groove 36 defined from at least two planar sidewalls 38, 40 and has an enlarged inlet end 42A and a narrower outlet end 43A. The respective upper edges 39, 41 of the sidewalls 38, 40 of the groove 36 lie in a reference plane RP having a reference axis R lying therein. The planar surfaces 34 also lie in the reference plane RP. The reference axis R extends in the reference plane RP from the inlet end 42 to the the outlet end 43 of the groove 36. Each point on the reference axis R is spaced in the reference plane RP an equal distance from the respective upper edges 39, 41 of the sidewalls 38, 40. The distance between the upper edges of the sidewalls decreases from the inlet end 42 to the outlet end 43 of the groove 36.
The surfaces of the sidewalls 38, 40 are equally and oppositely inclined with respect to the reference plane at an angle A greater than zero and less than ninety degrees. The angle of inclination A is determined by the lattice structure of the crystal, and in the case of (100) silicon, is 54.74 degrees. The projections of the sidewalls 38, 40 intersect in a line L that itself intersects the reference axis R forwardly past the outlet end 43 of the groove 36. The line L is inclined with respect to the reference plane RP at an angle B that is greater than zero degrees but less than ninety degrees. In the reference plane RP the upper edges 39, 41 of the sidewalls 38, 40 each converge toward the reference axis R at an angle C that is on the order of two and one-half to five degrees (2.5 to 5) degrees, and most preferably at about three (3) degrees. The angle B is dependent upon the values of the angles A and C and tyoically the angle B lies in the ange from about four (4) to five (5) degrees. As used herein a "fully funnel-like" channel is a channel that is defined by the cooperative association of at least two converging grooves. A "partially funnel-like" channel is a channel that is defined by one converging groove and a surface.
From the foregoing h may be readily understood that a "uniform width" groove is jne in which each point on the reference axis R is spaced in the reference plane RP a uniform distance from the edges 39, 41 of the sidewalls 38, 40 as one progresses from the inlet end 42 to the outlet end 43 of the groove 36. The sidewalls of a uniform width groove may be inclined with respect to reference plane RP, or they may extend perpendicularly to it, as desired. A channel formed from one or two uniform widtfr grσove(s) is termed a "uniform width" channel. Such a; channel may have a rectangular cross section in a plane perpendicular both to the reference plane and to the reference axis, assuming no inclination of the sidewalls of the groove.
A tapering groove is one in which the planar sidewalls are perpendicular to he reference plane but the distance in the reference plane between the reference axis and the edges of the sidewalls decreases as one progresses from the inlet to the outlet of the groove such that the extensions of the planar sidewalls intersect in a line that itself intersects perpendicularly with the reference axis.
In the preferred embodiment seen in Figures 3 and 4 the groove 36 is a converging groove, and more preferably, is a V- groove truncated by the presence of a third sidewall defined by a portion of the major surface 26 of the arm 22 in which it is disposed. The truncated V-groove has the same depth throughout its length, when measured along a dimension line erected perpendicular to the surface 34A of the abutment 32A in a direction extending toward the major surface 26A.
It should be understood thai the V-shape of the groove 36A may take alternate fotpts and remain within the
* contemplation of the invention. For example, as seen in Figure 4A, the groove 36A may be defined by only the first and second sidewalls 38A, 40A, respectively, in which event the groove 36A appears as a full V-shape throughout its length.
The apex 42A of the groove 36A thus appears throughout the full length of the groove 36A. Figure 4B shows another alternative arrangement in which a truncated V-groove (defined by the first and second sidew; s 38A, 40A, respectively, end the portion of the major surface 26A) extends for some predetermined axial distance while a full V-groove (defined by the first and second sidewalls 38A, 40A, respectively) extends for some second predetermined distance. Thus, as seen in Figure 4B, when measured along a dimension line erected perpendicular to the surface 34A of the abutment 32A in a direction extending toward the major surface 26A the depth that the groove 36A extends into the abutment 32A is greater at its inlet end 42 (as indicated by the dimension arrow 44A) than it is at its outlet end 43 (as indicated by the dimension arrow 46A).
The fully truncated V-groove shown in Figure 4 is preferred. For purposes of ease of manufacturability, as will be made clear herein, it is also preferred that the groove 36A does not converge throughout the full a. 1 distance through the abutment 32A. Owing to the provision of tabs 48A, 48B (Figures 1 and 5) formed near the ends of the abutments 32A, 32B, the sidewalls 38A, 40A defining the groove 36A do not converge throughout the full length of the groove, but define a short uniform width portion just past the converging portion of the groove 36A. The overall axial length of the groove 36 (including both the converging and the uniform width portit ) is on the order of three tenths (0.3) of a millimeter, while the uniform width portion of the groove occupies an axial length of one tenth (0.1 ) oi a mi'ϋmeter. As is believed best seen in Figure 5 the converging and nonconverging portions of the groove 36A have a common axis . )A associated therewith.
Again with reference to Figure 2, an extended enlargement region 54A having a planar surface 56A lies on the base portion 24A of the arm 22A spaced a predetermined axial distance 58A behind the abutment 32A. The distance 1
58A is on the order jσf one (1 ) millimeter. The surface 56A is coplanar wilh the surface 34A. The enlargement 54A is provided wilh a nonconverging, uniform width, truncated V- shaped trough 60A defined by inclined planar sidewalls 62A, 64A, respectively, and by a portion of the major surface 26A of the base portion 24A near the second end thereof. In the embodiment shown in Figures 1 and 2 the trough 60A is uniform in depth along its axial length, as measured with respect lo a dimension line erected perpendicular to the surface 56A toward the major surface 26A. The trough 60A communicates with a converging lead-in 68A. If desired, the walls 62A, 64A may be inclined with respect to each other so that the trough 60A may be a full V-shape or a partial V- shape, similar to the situation illustrated in connection with Figures 4A and 4B for the .groove 36A. Alternatively, the walls 62A, 64A defining the troughs 60A, 60B may be parallel or otherwise conveniently oriented with respect to each other. As is believed best seen in Figure 5 the trough 60A and the lead- in 68A have a common axis 70A. The length of the trough 60A and associated lead-in 68A is on the order of 1.59 millimeter.
Figure 5 is a plan view of one of the arms 22A. In the preferred implementation the axes 50A, 70A (respectively through the groove 36A and the trough/lead-in 60A/68A) are offset a predetermined distance 72 in the reference plane RP (the plane of Figure 5). Preferably, the offset 72 is al least one-half the difference between the diameters of the anticipated largest and smallest fibers to be positioned. As will become clearer herein offsetting the axes 50A, 70A of the structures 36A, 60A 68A facilitates the centering action of the positioning apparatus 20 by insuring that a fiber, as it is introduced into the apparatus 20, is biased to strike one of the sidewalls 38A, 40A forming the groove 36A (and analogously, the sidewalls 38B, 40B forming the groove 36B). This insures wall contact with the fiber al al least two spaced locations. However, the presence of the offset 72 necessitates additional manufac ϊng considerations, as will be discussed. It should be noteα that the force resulting from biasing the fiber in the manner just discussed (or the force on the fiber due to gravity) is much smaller in magnitude than the biasing force of the arms which serves to center the fiber on the reference axis.
In ihe assembled conditio he arms 22A, 22B are disposed in superimposed relationship one above the other, with the groove 36A, the trough 60A and the lead-in 68A on the one arm 22A ^gistering with the corresponding groove 36B, trough 60B and lead-in 68B jn the other arm 22B. The registered converging grooves 36A, 36B in the abutments 32A, 32B cooperate to define a generally fully funnel-shaped channel 92 having an input end 94 (Figure 4) and an output end 96 (Figures 4 and 5). (Note that if the tabs 48 are provided, the channel 92 so defined has a uniform width portion just preceding the outlet end 96 thereof.) The reference axis R extends centrally and axially through the channel 92. Preferably, the reference axis R lies on the intersection of the reference plane RP (which contains the conjoined surfaces 34A, 34B) with the plane containing the axes 50A, 50B of the converging grooves 36A, 36B.
The registered troughs 60 and lead-ins 68 cooperate to define a guideway 98 (Figure 2). Similarly, the axis R' through the guideway 98 lies on the intersection of the plane containing the conjoined surfaces 56A, 56B of the enlargements 54A, 54B (which is the reference plane in the preferred case) with the plane containing the axes 70A, 70B (Figure 5) of the trough/lead-in 60A/68A, 60L JB. The axes R and R' both lie in the reference plane RP (the plane of the surfaces 34A, 34B, 56A, 56B) although the axes R and R' are laterally offset with respect to each other in this reference plane by a predetermined offset distance 100. For a fiber the offset distance 100 is typief ly on the order of five (5) micrometers.
The inlet end 94 of the fully funnel-like channel 92 (best seen in Figures 4 and 5) is sized to circumscribe and thereby to accommodate a fiber F whose cladding layer L (or outside surface) has the largest expected outer diameter dimension. The outlet end 96 of the channel 92 (best seen in Figure 3) is sized to circumscribe and thereby to accommodate a fiber F whose cladding layer L (or outside surface) has a dimension somewhat smaller than the minimum expected outer diameter dimension of the fiber F. In practice, lo position an optical fiber having a nominal outer diameter dimension of one hundred twenty five (125) micrometers,, the, largest expected outer diameter dimension is on the order of one hundred twenty nine (129) micrometers while the smallest expected outer diameter dimension is on the order of one hundred twenty one (121) micrometers.
The dimension of each of the troughs 60A, 60B is such that the guideway 98 so ^formed by the registered troughs 60A, 60B is sized to accommodate a fiber F whose cladding layer L has the largest expected outer diameter dimension. Despite its dimension with respect to the fiber, the guideway 98 assists in the insertion of a fiber into the positioning apparatus 20 and is advantageous in this regard.
In the embodiment shown in Figures 1 through 5 the surfaces 34A, 34B on the respective arms 22A, 22B, respectively, are, when in a first, closed, position, either in contact with each other or, if desired, within a predetermined close distance to each other. For optical fibers the predetermined close distance is typically on the order of five (5) to twenty-five (25) micrometers. In this embodiment the planar surfaces 34A, 34B on the abutments 32A, 32B of the clips 30A, 30B are not secured to each other and may move to a second, centering, position, as will be described. The planar surfaces 56A, 56B on the respective arms 22A, 22B are secured to each other by any convenient means of attachment, as by fusing or soldering. It should be understood that any other mechanical securing expedient may be used to attach or otherwise hold together the surfaces 56A, 56B to each other.
The positioning apparatus 20 further includes, in the preferred instance, a mounting foundation 74 (Figures 1 and 2). The mounting foundation 74 is provided wilh a planar attachment surface 76 thereon. A step 78 in the mounting foundation 74 serves lo space the attachment surface 76 a predetermined clearance distance 80 from a second surface 82. The opposite major surface, e.g., the surface 28A, of the arm 22A is secured, as by fusing or soldering, to the planar attachment surface 76 on the foundation 74. Of course, it should be again understood that any alternative mechanical attachment expedient may be used to attach or otherwise hold together the second major surface of the arm to the foundation 74.
Although the second surface 82 of the foundation is shown in the Figures as being generally planar in the preferred case, it should be understood that this surface 82 may take any desired configuration. As will be more fully appreciated herein, so long as the opposite surface 28A of the arm 22A affixed lo the foundation 74 is, al least in the region of the clips 30A, spaced al leasl a predetermined clearance distance 80 from ihe second surface 82 (assuming the surface 82 is parallel to the surface ), the movement of the clip on the arm 22A attached to the loundation (in the drawings, the clip 30A) to be described will not be impeded. 22
When assembled, the clips 30A, 30B disposed at the ends of the arms 22A, 22B, respectively, are supported in a caπlilevered fashion from the conjoined enlargements 54A, 54B at the opposite end# of the arms. The arms 22A, 22B are rigid 5 in x-z plane, as delϊπecf by the coordinate axes shown in Figure 1. Moreover, the? relatively thin dimension of the central region 25A, 25B of 'the base portion 24A, 24B of the arms 22A, 22B axially intermediate the respective abutments 32A, 32B and the enlargements 54 A, 5 B acts as a flexure and permits
10 each arm 22 to flex, springboard fashion, in the directions of the arrows 88 in the y-z plane. As used herein it should thus be appreciated that a flexure is a spring member that is rigid in one plane and is constrained lo flex in the orthogonal plane. It should further be appreciated that when a clip 30A,
15 30B is deflected in its corresponding respective direction 88A, 88B, the resiliency of the thinner central region 25 A, 25B of the base 24A, 24B, acting as a flexure, defines means for biasing the clips 30A, 30B toward the first, closed, position. The biasing force acts on the clip 30A, 30B in a direction shown by
20 the arrows 90A, 90B, counter to the direction of motion 88 A, 88B of the arms. The biasing forces must be substantially equal and in opposite directions. In general, whatever the number of arms used in the positioning apparatus, the force on each arm passes through the reference axis and the sum of
25 forces when in the centering position position substantially equals zero. Biasing means employing the thinner central region of the base 24 as a flexure (as shown in the Figures 1 to 4) is preferred, because when implemented in a single crystal material using a microfabrication technique precise control of
30 the biasing forces is able to be attained. Typically the bias force on each arm is on the order of five (5) grams.
It should be understood that any other convenient mechanism may be used to define the means for biasing the 23
arms and ihe clips 30 thereon toward the closed position so long as the force on each arm passes through the reference axis and the sum of forces on the arms when they are in the centering position is substantially equal to zero. Whatever form of biasing means is selected the bias force must increase with deflection of the arm.
-o-O-o-
Having defined the structure of the positioning apparatus
20, the operation thereof in positioning a point P on the end face E of an optical fiber F along a predetermined reference axis R may be readily understood in connection with Figures 5 through 7.
In operation the fiber F is inserted into the pos; "oning apparatus 20 in the direction of the arrow 102 (Figure 6A). The lead-in portions 68A, 68B (Figure 1) cooperate to guide the fiber F into the guideway 98 (Figure 2) defined by the registered troughs 60A, 60B in the enlargements 54A, 54B
(Figure 1). Because the axis R' of the passage 98 is of -t from the axis R of the fully funnel shaped channel 92 the guideway 98 serves to guide the face E of the fiber F toward the inlet end 94 of the channel 92 at a predetermined azimuth with respect to the axis R.
As a result the end face E of the fiber F enters the channel 92 and is initially displaced through contact with al least one of Ihe sidewalls 38A or 38B, 40A or 40B (or portions of the major surface 26A, 26B, if these are used to define the grooves 36A, 36B, as in Figure 4) on one of the clips 30A, 30B, respectively, lo the extent necessary to place a predetermined point P on an end face E of the fiber F into alignment with the reference axis R. 24
At some point on the path of axial insertion of the fiber F into the channel 92, as the end E of the fiber F moves toward the outlet end 96, the outer diameter of the cladding layer L of the fiber F exceeds the dimension of the channel 92. The arms 22A, 22B respond to a force in the directions 88A, 88B imposed thereon by the fiber F by moving against the biasing force from the first, closed, position, shown in Figures 7A, 7B, toward a second, centering, position showing in Figures 8A, 8B. In the centering position the clips 30A, 30B open against the bias force acting in the directions 90A, 90B generated by the flexing of the arms 22A, 22B, to separate the surfaces 34 A, 34B thereon. However, this movement of the arms 22A, 22B from the first toward the second position maintains the point P on the end face E of the fiber F on the reference axis R. The end face E of the fiber F thus exits through the outlet end 96 of the fully funnel shaped channel 92 with the point P precisely aligned with (i.e., within one micrometer of) the reference axis R, as is shown in Figures 8 A, 8B. The fiber F is held in this position by contact wilh ihe sidewalls 38A, 38B, 40A, and 40B.
If the tabs 48A, 48B are formed on the abutments 32A, 32B these tabs cooperate lo define a passage of uniform width along its axial length that communicates with the outlet of the funnel-like channel. The fiber F passes through and emerges from such a conduit wilh the point P on the end face of the fiber still along the reference axis R.
It should be noted llrøt the movement of the arms could be other than the flexing thereof as described heretofore. It therefore lies within |ιe contemplation of this invention to have the arms move in any other manner, as, for example, by any form of pinned or jointed (articulated) motion.
o-O-o- With reference now to Figures 9 through 12 an alternate embodiment of the positioning apparatus 20* in accordance wilh the present invention is shown. In this embodiment the arms 22' are, similar to the embodiment earlier discussed, articulably movable in cantilevered fashion wilh respect to each other against the bias of the flexure defined by the central portion 25' thereof. However, the grooves 36' formed in the arms 22' are not converging grooves, but are uniform width grooves. Accordingly the channel 92' formed by the cooperative association of the arms 22' when superimposed one on the other is a uniform width channel. The maximum dimension of such a channel 92' in the plane perpendicular to the reference R is less than the outside diameter of the smallest anticipated fiber F.
A further modification to the positioning apparatus 20' may be seen from Figure 12. It is first noted that the planar walls 62', 64' of the troughs 60' are parallel, rather than inclined with respect to each ;her. Moreover, the offset 100' between the axes R and R' lies in the vertical plane, that is, in the plane containing the axes 70' of the troughs 60', as opposed to being offset laterally (i.e., in the plane containing the surfaces 56'). The lead-in portions 68'A, 68'B are ommitted here but may be provided.
In operation, a fiber F is inserted into the positioning apparatus 20' and guiued by the passage 98' defined by the registered troughs 60'A, 60'B. Because the axis R' of the passage 98' is vertically offset from the axis R of the channel 92' the surface 26'B of the arm 22'B bounding the passage 98' serves to guide the fiber F toward the inlet end 94' of the channel 92'. The fiber F enters the channel 92' and contacts with the edges of the sidewalls 38'A, 38'B, 40'A and 40'B. Due to the sizing of the grooves 36'A, 36'B the fiber F does not touch the major surface 26'A, 26'B of the arms 22'A, 22'B, 26
respectively. The, fiber may be chamfered or tapered or a mechanical device may be used lo facilitate insertion of the fiber into the channel 92'.
Since the fiber F exceeds the dimension of the channel 92' the clips 30'A, 30'B are displaced from the first, closed, position toward a second, centering, position. This movement of the clips 3ϋ'A, 30'B maintains the point P on the end face E of the fiber F on the reference axis R. The end face E of the fiber F thus exits through the outlet end 96' of the channel 92' with the point P precisely aligned on the reference axis R. The fiber F is held in this position by contact with the edges of the sidewalls 38'A, 38'B, 40'A, and 40'B, as indicated by the character LC.
The embodiment of Figures 9 to 12 can be further modified, as seen in Figures 13 to 16. In this modification, the arm 22"B differs from those shown earlier in that no groove is provided therein. In this embodiment, if the groove is a converging groove, a partially funnel-like channel is defined. The fiber F is guided by contact against the major surface 26"B and held in position on the reference axis R by contact with the major surface 26"B and the edges of the sidewalls 38'A, 38'B, again as indicated by the character LC.
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Figures 17 and 18 are exploded and assembled perspective views, generally similar to Figures 1 and 2, of another alternate embodiment of a positioning apparatus 20"' in accordance witli the present invention while Figure 19 shows the end view Iftereof. In this embodiment, instead of the arms being articulably movable as described earlier, the arms are fixed relative to each other. Each of the arms 22"'A and 22"'B has a converging groove therein and the channel 92"' formed by the cooperative association of the arms 22"' when superimposed one on the other is fully funnel-like in form. The channel 92"' defines a minimum dimension in the plane perpendicular to the reference R that is, near its outlet end, less than the outside diameter of the smallest anticipated fiber F.
In operation, a fiber F is inserted into the positioning apparatus 20'" and guided through the passage 98'" toward the inlet end 94'" of the channel 92"'. The fiber F enters the funnel-like channel 92"' and is guided by contact with one or more of the sidewalls 38'A, 38'B, 40'A and 40'B and/or major surfaces 26"'A, 26"'B to place the point P of the fiber F on the axis R. However, since the arms 22"' are fixed with respect to each other, the fiber F can only advance within the channel 92"' to the axial location where the outer diameter of the fiber F equals the local dimension of the channel 92"'. At this axial location within the channel the fiber is held in position by a minimum of four point contacts (indicated by the characters PC) between the fiber F and each of the sidewalls 38'A, 38'B, 40'A, and 40'B. The dimension of the channel is such that the fiber is not able to contact the major surface of the arms 22"' when it is held alon,; the reference axis R. Figure 20 illustrates the fiber as the same is held within the channel 92"'. The axial spacing 104 between the end face E of the fiber F and the outlet end 96'" of the channel 92"' varies, dependent upon the outer diameter dimension of the fiber F.
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The positioning apparatus in accordance with any of the above-described embodiments of ihe invention may be used in a variety of applications which require the precise positioning of a point P on the end face E of a fiber F along a reference axis R. 28
In Figures 21 and 22, a pair of positioning apparatus 20-
1.
20-2 (corresponding to the embodiment shown in Figures 1 and 2) are arranged to define a fiber-to-fiber connector generally indicated by the reference character 120. In this arrangement the apparatus 20-1 , 20-2 are confrontationally disposed wilh respect to the other so thai the outlet ends 96 of the respective channels 92 therein are spaced a predetermined distance 122 with the respective reference axes R therethrough being collinear. To effect such an arrangement the foundation 74 is extended in an axial direction and each axial end thereof is provided with a planar attachment surface 76. Each positioning apparatus 20-1 , 20-2 is mounted to its respective attachment surface .
The fibers F-ϊ and F-2 to be connected are inserted into the lead-ins 68 of the respective positioning apparatus 20-1 , 20-2. Each positioning apparatus 20-1 , 20-2, acting in the manner described above, serves to place the point P on the end face E , of the respective fiber F-1 or F-2 along the collinearly disposed axes R'. The fibers F- 1 , F-2 are inserted in to the respective apparatus 20-1 , 20-2 until the' end faces E, E' abut. The ends E of the fibers F-1 , F-2 are secured due to the above- described holding action of the positioning apparatus. If desired an suitable index matching adhesive, such as an ultraviolet curing adhesive such that manufactured and sold by Electro-Lite Corporation, Danbury, Connecticut as number 82001 ELC4480, may be used.
The fiber-to-fiber conneclor may be implemented using any of the above-discussed alternative embodiments of the positioning apparatus. In the event a pair positioning apparatus as shown in Figure 17 is used (see Figures 23 and 24), the confronting ends of the positioning apparatus 20"'-l , 20"'-2 are preferably abutted and secured, or the pair of positioning apparatus formed integrally with each other. The spacing 122 between the end faces E of the fibers F-1 , F-2 is, in this embodiment, defined by the sum of the distances 104-1 , 104-2. The spacing 122 is filled with an index matching material, such as the adhesive defined above. To this end, an access port 124 is provided to permit the introduction of the irsdex matching material into the region between the confronting end face of the fibers F-1 , F-2.
Prior to insertion into the positioning apparatus (of whatever form) it should be understood that the jacket J (Figure 29) of the fiber F is stripped in its entirety a predeterm _ιed distance from the free end thereof. The exposed portion of the fiber is cleaned with alcohol. The fiber is cleaved to form the end face E. If desired the end face E may be ground into a convex shape lo yield a point or be lensed.
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If desired the fiber-to-fiber connector 120 may be disposed in a suitable housing 130 (figure 25). The preferred form of the housing 130 is generally similar to that disclosed in United States Patenl 4,784,456 (Smith), assigned lo the assignee of the present invention. This patent is hereby incorporated by reference herein. The housing 130 includes a base 132 and a cover 134. The base 132 is, in all cases, provided wilh a recess 136 that is sized lo closely receive the connector 120. If the connector 120 is realized using any form of the positioning apparatus that articulates, the cover 134 must be provided with a corresponding recess 138 located so as to permit the articulating motion of the arms of positioning apparatus used to form the connector. If the connector ι20 is realized using the form of the positioning apparatus shown in Figures 23 and 2 -. , the recess 138 need not be provided. Such a housing 130 is shown in Figure 28. 30
The cover 134 is segmented into three sections, 140A, 140B, 140C, each which is hinged to the base 132. The base 132 has, adjacent to each end of the recess 136, V-shaped grooved regions 142/¥, 142B. The top end sections 140A, 140B each contain respective generally tapered lands 143 A, 143B. Each of the lands has serrations 145A, 145B respectively thereon.
In use a connector is inserted in the recess 136 of the housing 130. It is tπere held in place by friction but may be otherwise secured if desired. The central section HOC of the cover may then be closed, if desired. An optical fiber having a predetermined length of its jacket J stripped and cleaned, is inserted through one of the V-shaped grooved regions 142A,
142B to dispose the stripped end of the fiber into the connector 120. The grooved region serves to properly orient and position the fiber with respect to the connector 120 in ihe recess 136. The associated top end section 140A, 140B, as the case may be, is then closed and latched lo the corresponding portion of the base 132 (Figure 25, with the fiber ommitted for clarity). When the top is secured to the base the serrations 145 act againsl the jacket of the fiber to urge, or to bias, the fiber toward the connector. A second fiber is correspondingly introduced into the housing and connector in an analagous manner. If not already done so, the central section 140C of the cover is then closed. The housing 130 is preferably formed by injection molding.
As seen in Figure 29, in another form the housing 130 may be implemented using a mass 160 of index matching material, such as that identified above. The mass 160 extends over both the connector 120 (to embed the same therein) and some predetermined portion of the jackets J of the fibers F-1 , F-2. -o-O-o-
The reference axis R on which the point P of the fiber F is positioned may itself extend collinearly with the axis X of any of a variety of devices. Accordingly, a positioning apparatus 20 may be used to accurately position the point P on the end face E of the fiber F with respect to the axis X of a particular device 170. Figures 30, 31 and Figures 32, 33 illustrate several examples of the use of a positioning apparatus 20 to locate a fiber F along an axis X of a device 170. The device 170 may, for example, be realized by any active optical component, such as a solid state laser, a photodiode, a light emitting diode, whether these devices are edge active devices or surface active devices. Although in the discussion that follows the reference character 20 is used lo indicate the positioning apparatus, it should be understood that any one of the embodiments of the positioning apparatus heretofore described may used.
When used in connection with an edge active device 170 ihe arrangement in Figures 30 and 31 is preferred. In this arrangement the foundation 74 is axially extended to define a pedestal 174 at the axial "nd thereof. The upper surface 176 of the pedestal 174 defines a planar attachment surface. The surface 176 is spaced a predetermined distance above the attachment surface 76 or otherwise located such that when the active optical component 170 is mounted the surface 176 the axis X of the device 170 and the reference axis R are collinear. With the axes R and X collinear, the positioning of the point P on the fiber F along the axis R will automatically position that point P in the same relationship wilh the axis X. The device 170 must be accurately mounted on Ihe surface 176 so that its axis X is collinearly aligned wilh ihe axis R. 32
To mount the device 170 the surface 176 may be provided with a layer of solder layer, such as a gold/tin solder. The device 170 may have a corresponding layer of the same material. The device 170 is positioned on the surface 176 using a suitable micrσpositioning apparatus, such as a vacuum probe. The device is aligned to the edge, heated above the melting point of the solder and cooled, so that the solder forms a bond.
When used with- surface active device, as seen in
Figures 32 and 33, the actiΛje surface of the device 170 is secured lo the front surface 178 of the pedestal 174. Attaching the device to the front surface 178 is believed to provide sufficient bonding area to secure the device 170 to the positioning apparatus 20. ' The surface 176 of the pedestal 174 is relieved to avoid obstruction between the active region of the device 170 and the end face E of the fiber F.
It should also be appreciated, as is illustrated in Figure 31 A, that the positioning apparatus in accordance with any one of the embodiments heretofore described may be configured to accurately position a lens, such as a ball or a rod lens L, with respect to the axis of the device 170 (whether the same is an edge active or a surface active device). The positioning apparatus would be modified to provide a seat 3 I S in the clips 30 thereof sized to accept the lens L.
o-0-o- The photolithographic microfabrication technique used to manufacture a positioning apparatus 20 may be understood from the following discussion take , in connection with Figures 34 to 40. Although the discussion is cast in terms of the manufacture of a fiber-lo-fiber connector 120 using the preferred embodiment of the positioning device 20, as shown in Figure 22, the teachings are readily extendable to the manufacture of any of the embodiments of the positioning apparatus heretofore described, including their use in the various other applications previously set forth.
A silicon wafer 200 having an appropriate predetermined crystallographic orientation is the starting point for fabrication of the arms 22 of a positioning apparatus 20 in accordance with the present invention. It should be understood that other single crystalline substrate materials, such as germanium, may be used provided appropriate alternative etchants a_ιd materials compatible with the selected alternative substrate are used. The wafer 200 is polished on at least one surface. Suitable silicon wafers are available from SEH America, Inc., a subsidiary of Shin-Etsu Handotai Co. Ltd., Tokyo, Japan, located at Sparta, New Jersey. It should be understood that the wafer 200 can be of the "p-type", "n-type" or intrinsic silicon.
The substrate material is preferably ( 100) surface silicon because this material can be eiched by anisotropic etchants which readily act upon the (100) crystallographic plane but substantially do not etch the ( 1 1 1 ) plane. As a result the preferred truncated V-shaped grooves 36A, 36B, the troughs 60A, 60B, the lead-ins 68A, 68B and the central region 25A, 25B of the arn 22A, 22B between the abutments 32A, 32B and the enlargements 54A, 54B are easily formed. The width and depth of such featur s are dependent upon the preselected width of the opening in the photolithographic mask being used and the time during which the elchants are permitted to act. Etchants operate on 100 surface silicon in an essentially self- limiting manner which property is useful in forming a full V-groove. One of skill in the art will recognize that if other cross-section configurations are required, other predetermined crystallographic orientations of the silicon may be used. For example, if square cross-section features are desired, (110) surfaces silicon wafers can be used. Other cross sectional configurations for the features are, however, significantly more expensive and, as will be seen later, would require a more complicated configuration to obtain the fiber centering action equivalent to thai inherent in a V-groove.
Figure 34 is a plan view of the wafer 200. The wafer 200 has peripheral flats 201 and 202, as specified by the SEMI Standard. The flats 201 , 202 primarily indicate orientation of the crystallographic structure of the silicon and are' also used for wafer identification and mask alignment. The longer flat 201 indicates the direction of crystallographic plane (1 10). The shorter flat 202 is placed a predetermined angular amount on the periphery of the wafer with respect to the flat 201 , the magnitude of the angle depending upon the doping of the crystal.
As will be developed, the peripheral regions 203 of the wafer 200, when prepared, carry alignment grooves, while the central region 204 of the wafer 200 has the structural features of the arm or foundation, as fhe case may be, of the positioning apparatus formed thereon.
Figure 35 shows a mask 210 with a patterns 212 of orthogonal alignment grooves thereon. The grooves in each pattern 212 are graduated in size lo accommodate various sized (diameter) quartz alignment fibers. The grooves 212 have a V-shaped cross section to accept fibers ranging in width from about 0.004825 inches (0.123 mm) to 0.005000 inches (0.127 mm) in 0.039370 inch (0.1 mm) steps, five grooves 212 having been illustrated. The groove width (at the open top of the groove) is larger than the diameter of the fiber so that the center of the fiber is substantially coplanar with the surface of the wafer when the fiber is disposed in its associated groove. Accordingly, for a 0.123 mm fiber, a groove 0.1506 mm is provided. Similarly, for a 0.124 mm fiber, the open top dimension of the groove is 0.1518 mm. For a 0.125 mm fiber, the open top dimension of the groove is 0.1531 mm; for a 0.126 mm fiber the open top dimension of the groove is 0.1543 mm.; and for a 0.127 mm fiber, the open top dimension of the groove is 0.1555 mm.
A central area 214 of the mask 210 has provided thereon a repetitive pattern 220 (one of which is shown in Figure 36) containing to a predetermined number of structural features (i.e., arms or foundations) of the positioning apparatus 20 being formed. Since the typical wafer 200 is about 3.9381 inches (101.028 mm) in diameter and a typical connector 120 measures about t!,ree hundred fifty (350) micrometers at the widest location and is about two thousand eight hundred (2800) micrometers in length, the siructural features for approximately one thousand ( 1000) connectors 120 may be formed from the central region 204 of the wafer 200.
Figure 36 is an enlarged view of a portion 220 of the pattern provided on the central region 214 of the mask 210. In Figure 36, the pattern illustrated is that used to form a plurality of conjoined arms 22 used in a connector 120 (Figure 22). The pattern 220 is formed on the surface of the central region 214 of the mask 210 using a well-known step and repeat process to cover the entire area.
The repetitive pattern 220 shown in Figure 36 is comprised of ■ plurality of columns 224 which are defined between an array of adjacent parallel scribe lines 226 and a first and a second separation line 227 A and 227B. Each column 224 contains ten (10) discrete zones 228 A through 228E that are symmetrical withm the column 224 about a cutting line 230.
Seen between two next adjacent scribe lines 226 is the configuration of two arms 22 joined front end to front end. Seen between three next adjacent scribe lines 226 is the configuration of two arms 22 joined lengthwise side to side. The zone 228A corresponds to features defining the region of the lead-in 68 A of an arm 22A. The zone 228B corresponds to features defining the region of the trough 60A of the arm 22A. Similarly, zone 228C corresponds to the central portion 25A of the arm 22A, while the zone 228D corresponds to features defining the region oϊ the converging groove 36A on the arm 22A. The axis 50A of the converging groove 36A is offset from the axis 70A of the trough 60A by the offset distance 100. Finally, if provided, the zone 228E corresponds to features defining the region of the tabs 48A of an arm 22A. Note that in the mask illustrated in Figure 36 the position of the offset 100 on one side of the cutting line 230 is reversed from the position of the offset 100 on the opposite side of the cutting line, although this arrangement is not necessarily required.
The repetitive pattern for a mask of the arm 22B will be similar to that shown in Figure 36 except that the direction of the offset distances 100 for the arm 22B will be the mirror image of the pattern for Ihe arm 22A. As will be come clearer herein, this mirror image relationship between the offsets is necessary so that so J,hat features on the resulting arms 22A, 22B will register with each other when one is inverted and superimposed on the other. Of course if the offset 100 is eliminated, masks for the arms 22A and 22B will be identical. The cross-hatched areas shown in Figure 36 preferably correspond to those areas of the central region of the wafer 200 that will be protected by a layer of resist material (as will be described) while the areas shown without hatching will be left unprotected during subsequent etching steps. A negative resist is employed but it should be apparen' that the location of the hatched and clear areas of Figure 36 may be reversed if desired. This would alter somewhat subsequent steps, but in a manner known to those in the art.
Figures 37A through 37E illustrate the process steps whereby a wafer 200 of crystalline silicon may be formed into an array of arms 22A corresponding to the array shown on the mask of Figures 35 and 36. As seen in Figure 37A the wafer 200 is preliminarily covered with a layer 232 of a material that acts in a manner similar to a mask. Silicon nitride (SJ3N4) is preferred, and is surfaced onto the polished operative surface 200S of the silicon wafer 200 by thermally growing the silicon nitride layer in an oxygen atmosphere at elevated temperature (circa seven hundred fifty (750) degrees Celsius), as is known. As indicated, silicon nitride is used because available etchants that attack silicon will also attack known photoresists but will not affect silicon nitride. A suitable nitride layer is grown onto the wafer by CVD Systems and Services, Incorporated, Quakertown, Pennsylvania.
The layer of silicon nitride 232 is then covered with a photoresist 234. Preferred "s a positive resist, such as the mixture of 2-ethoxyelhyI acetate, N-butyl acetate and xylene sold by Shipley Company, Incorporated of Newton,
Massachusetts, as "Microposil Photoresist" 1400-37. The resist is spun onto the surface of the silica nitride in accordance with instructions set forth in he Shipley Microelectronic Products Brochure (1984) using standard apparatus such as that available from Headway Research Incorporated of Garland, Texas under model number ECR485.
The mask 210~ is mounted atop the wafer 200 and is aligned wilh respect to the flats 201, 202 of the wafer 200 using alignment bars 235. Thus, in a finished wafer the alignment grooves 212 are precisely positioned with respect to the flats on the wafer through the use of alignment bars 213 on the mask. The wafer 200 is exposed to ultraviolet light through the mask 210 and subsequently developed.
Since a positive resist is used the unexposed areas of the resist are washed away using de-ionized water, leaving the layered arrangement of exposed, hardened resist 234, silica nitride 232 and wafer 200, as shown in Figure 37B.
Next the pattern of the mask 210 is etched into the silica layer 232. Phosphoric acid (H3PO4) is preferred. This step results in the arrangement shown in Figure 37C. Those skilled in the art will recognize that process variables such as, for example, concentration, time and temperature are all adjusted appropriately to optimize results in all of the wet processing steps described.
Thereafter, a second, differential, etching step is performed to etch the silicon to form the features of the arms 22A. Preferably using an anisotropic etchant such as ethylene diamine ("ED") pyrocatechol ("P") and water. A mix of 750 ml ED, 120 gm P and 240 ml water is preferred. A two-step etch using potassium hydroxide (KOH) may also be used if desired. This etching produces the structural feature in the surface of the silicon illustrated schematically in Figure 37D by reference character 236. The depth of the feature 236 is controlled by controlling the etching lime, as is well known. Of course, differential etching is self-limiting for the inside angles of the structure, if left to proceed.
The silicon nitride layer 232 is then removed by etching with phosphoric acid and a layer of silica, i.e., silicon dioxide, is grown on the surface. Next, resist is deposited on the surface of the wafer and is imaged through a mask, as shown Figure 38. This results in a layer 238 of hardened resist being formed on those predetermined portions of the wafer that are to be bonded (corresponding to zones 228C through 228E and to troughs 60 (see Figure 36)).
The silicon layer is then etched from areas that are not to be bonded (See, Fgiure 37E) using hydrofluoric acid (HF). The resist layer 238 is stripped using acetone, leaving a finished wafer ready for bonding.
This completes the fabrication of the first wafer 200 having the array of arms 22A thereon.
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As noted earlier, since the axis of the guideway 98A is offset from the axis of the groove 92A, the mask for the arms 22B is not identical with the mask used to form the arms 22A. Accordingly, a second wafer having an array of arms 22B thereon must be prepared in accordance with the method steps illustrated in Figure 37. The finished second wafer (not specifically illustrated but hereinafter referred to by character 200') is similar in all respects except in location of the offset 100.
A third wafer 200" is prepared using a foundation mask, a portion of which is shown in Figure 39. Figure 39 is an enlarged view of a portion of the pattern 220' provided on the central region of the foundation mask (analagous to the pattern of the arm mask shown in Figure 36). The repetitive pattern 220' is comprised of a plurality of columns 244 which are defined between an array of adjacent parallel scribe lines 246 and a first and a second separation line 248A and 248B. Each column 244 contains four (4) discrete zones 250 that are symmetrical v?ilhin the column 244 about a center line 252. The zones 250A deπrte mounting surface 76 on a foundation 74. The zones 250β correspond to the surfaces 82 provided on the foundation. The wafer 200" containing the foundations 74 is exposed in a manner analagous to that shown in Figure 37, wilh the exception that the exception that the solder mask exposure is not carried out. However, the layer of silica is removed from the surface of the wafer 200".
Having preparέd wafers for the arms 22A (the wafer 200), the arms 22B lhe wafer 200') and the foundations 74
Tr
(the wafer 200"), the final assembly of the connector 120 may be made as is shown in Figure 40.
The wafer 200' is placed on top of the wafer 200. The registration of the features on the wafer 200' to those on the wafer 200 is effected using at least two and preferably four lengths of a stripped optical fiber and the corresponding appropriate one of the alignment grooves, in each array 212 of grooves. The diameter of each length of the optical fiber is measured by micrometer, accurate to plus or minus 0.5 micrometers. Each of the fibers is placed in groove in the groove array 212 that most closely corresponds lo the measured diameter. - Each alignment fiber thus sits in the selected alignment groove such that the axis of the alignment fiber lies in the plane of the surface of the wafer 200 with the remaining portion of each fiber protrudes above that surface. The wafer 200' is inverted and placed atop the wafer 200 with the corresponding grooves in the wafer 200' rect ng the protruding portions of the alignment fibers thereby to precisely align the pattern of the two wafers. Since 5 the alignment grooves on each wafer are formed simultaneously with the formation of the features on the wafer, and since the mask for each wafer is formed ontically one from the other, precise alignment between the wafers is achieved. It is noted in Figures 40A and 40B only one of the fibers 254 and l O grooves 121 is shown, for clarity of illustra'»on.
The assembly of superimposed wafers 200, 200' shown in Figure 40A is bonded in a wet controlled atmosphere furnace according to methods described in the paper by Shimbo et al.,
15 "Silicon-to-silicon dire ct bonding method" published 10/86 in the Journal of Applied Physics, and in the paper by ' Lasky et al., "Silicon on Insulator (SOI) By Bonding and Elchback", IEDM 85. As seen in Figure 40B the exterior surface 256' of the wafer 200' is lapped to reduce its thickness from it original thickness
20 (typically approximately seventeen (17) micrometers) to a final thickness of five (5) micrometers.
The resulting bonded structure is inverted and the exterior surface 256' of the wafer 200' is mounted atop the
25 wafer 200". The alignment of these wafers is effected using a fixture employing quartz blocks 260 abutting against the flats 201 , 202 of the wafer 200. The wafer 200" is then bonded to the wafer 200". It is to be understood that other bonding techniques, such as those discussed in the paper by
30 Wallis and Pomerantz "Field Assisted Glass-Metal Sealing" published 9/69 in the Journal of Applied Physics may be used to bond the wafers. Still other alternate bonding techniques would include metallic or glass solder bonding. The exterior surface 256 of the wafer 200 is then lapped until the dimension of the wafer 200 is that of the wafer 200'. Thus, the substantial equality of the biasing forces imposed by the flexure is provided.
The resultant three wafer bonded stack shown in Figure 40D may then be cuL Only the top two wafers 200, 200' of the bonded stack (containing the arms 22-1 B, 22-2B and the arms 22-1 A, 22-2A, respectively, Figure 22) are first cut along the lines in the wafers corresponding to the cutting lines 230, 230' on the arm masks (Figure 36). This cut is made using a blade that is on the order of 0.003 inches to create the distance 122 in Figure 22. The bonded stack is thereafter cut, using a blade that is 0.015 inches thick, along the lines in the wafers corresponding to the separation lines 227A, 227B on the wafer 200, the separation lines 227A', 227B' on the wafer 200', and the separation lines 248A, 248B on the wafer 200", as well along the scribe lines 226, 226' and 246 (on the respective wafers 200, 200' and 200") all of which are registered with each other, thereby to yield from the bonded stack about one thousand of the fiber- to- fiber connectors 120.
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Those skilled in the art, having the benefits of the teachings of the present invention as hereinabove set forth, may impart numerous modifications thereto.
For example, as seen in Figure 42, in addition lo the various embodiments of the two-armed configurations for the positioning apparatus of the present invention previously disclosed, it lies within the contemplation of this invention for a positioning appaiatus to exhibit more than two arms 22. In this regard Figures 42A lo 42C illustrate a positioning apparatus having three arms 22A, 22B and 22C while Figures 42D through 42F illustrate a positioning apparatus having four arms 22Λ, 22B, 22C and 22D. The extension to even greater number of arms would be readily apparent to those skilled in the art. 5
In Figure 42A each the arms are configured similar to the form of the arms discussed above. The arms may, if desired carry a groove, although il should be understood that such is not required. In Figures 42B and 42E the arms are configured
10 from rods. Although ihe rods shown as round in cross section . il should be understood that they can have any desired alternate cross section. In Figures 42C and 42F the arms are configured in a generally planar bar form. In Figure 42D the four arms may be formed by sawing the upper and lower arms
I f (indicated by the characters 22A, 22B in Figures 1 to 4) along a cut line extending perpendicular to the major suraces 26 and 28 of each of the arms.
However configured the arms are shown in Figures 42A 0 through 42F as angularly juxtaposed in a surrounding relationship to the channel 92 defined their cooperative association. Similar lo the situation described heretofore the resiliency of the arms defines the biasing means which urge the arms toward the closed position. However, it should be 25 understood that the biasing means may be otherewise defined, so long as the force on each arm passes through the reference axis and the sum of forces on the arms when they are in the centering position is substantially equal to zero. Whatever form of biasing means is selected the bias force must increase 3t with deflection of the arm. The arms act against the fiber F inserted into the channel along the various lines of contact LC illustrated in Figure 42 to maintain the predetermined point on the fiber on the reference axis R. It should be understood that such modifications as herein preented and any others are to be construed as lying within the contemplation of the present invention, as defined by the appended claims.
WHAT IS CLAIMED IS:

Claims

1. An opto-electronic component comprising, in combination:
a positioning apparatus comprising at least a first and a second arm, the first arm being mounted to a foundation, the foundation having a pedestal thereon, each arm being movable from a first, closed, position to a second, centering, position,
in the closed jsition the arms cooperating to define a channel having a reference axis therethrough, the channel having an inlet end and an outlet end,
means for biasing each of the arms toward the first, closed, position such that the force on each arm passes through the reference axis and such that the sum of forces on the arms when in the centering position is substantially equal to zero,
eat of the arms being arranged such that an optical fiber introduced into the inlet end of the channel with the axis of the fiber spaced from the reference axis is initially displaceable by contact with at least one of the arms to place a predetermined point on the fiber inio alignment wilh the reference axis,
the arms being responsive to further axial movement of the fiber through the channel by moving against the bias force toward the centering position to maintain the point on the fiber on the reference axis; and an opto-elecironic device mouted to the pedestal, the opto-electronic device having a reference axis therethrough, the reference axis of the opto-electronic device aligning with the reference axis of the channel.
2. An opto-electronic component comprising, in combination:
a positioning apparatus comprising at least a first, a second arm and a third arm, the first arm being mounted to a foundation, the foundation having a pedestal thereon, each arm being movable from a first, closed, position to a second, centering, position,
in the closed position the arms cooperating to define a channel having a reference axis therethrough, the channel having an inlet end and an outlet end,
means for biasing each of the arms toward the first, closed, position such that the force on each arm passes through the reference axis and such that the sum of forces on the arms when in the centering position is substantially equal to zero,
each of the arms being arranged such that an optical fiber introduced into the inlet end of the channel with the axis of the fiber spaced from the reference axis is initially displaceable by contact with at least one of the arms to place a predetermined point on' the fiber into alignment with the reference axis regardless of the diameter of the fiber,
the arms being responsive to further axial movement of the fiber through the channel by moving against the bias force toward the centering position to maintain the point on the fiber on the reference axis; and 47 an opto-electronic device mouted to the pedestal, the opto-electronic device having a reference axis therethrough, the reference axis of the opto-electronic device aligning with the reference axis of the channel.
3. An opto-electronic component comprising, in combination:
a positioning apparatus comprising a first and a second arm, the first arm being mounted to a foundation, the foundation having a pedestal thereon, at least the first arm having at least a first and a second sidewall cooperating to define a groove therein, the arms being arranged in superimposed relationship, each arm being movable from a first, closed, position Ϊ a second, centering, position,
means for biasing each of the arms with a substantially equal and oppositely directed biasing force toward the first, closed position,
in the closed position the arms cooperating to define a channel having a reference axis therethrough, the channel having an inlet end and an outlet end,
each of the arms being arranged such that an optical fiber introduced into the inlet end of the channel with the axis of the fiber spaced from the reference axis is initially displaceable by contact with at least one of the arms to place a predetermined point on an end face of the fiber into alignment with the reference axis,
the arms being responsive to further axial movement of the fiber through the channel by moving against the bias force toward the centering position to maintain the point on the face 48 of the fiber on the reference axis by contact between the fiber and both the first and the second arms; and
an opto-electronic device mounted to the pedestal, the opto-electronic device having a reference axis therethrough, the reference axis of the active device aligning with the reference axis o the . channel.
4. The opto-electronic component of claim 3 wherein the first and the second sidewalls in the first arm cooperate to define a converging groove therein, the channel being partially funnel¬ like in shape over at least a predetermined portion of its axial length.
5. The opto-electronic component of claim 4 wherein the second arm has a planar surface thereon.
6. The opto-electronic component of claim 4 wherein the second arm has at least a first and a second sidewall disposed therein, the first and second sidewalls in the second arm cooperating to define a converging groove therein, the converging groove in the first arm and the converging groove in the second arm cooperating to define the channel, the channel being fully funnel-like in shape over at least a predetermined portion of its axial length.
7. The opto-electronic component of claim 3 wherein the first arrή has at least a first and a second sidewall disposed therein, the first and the second sidewalls in the first arm cooperating to define therein a groove having a uniform width dimension throughout its length, the channel being rectangular in cross sectional shape over at least a predetermined portion of its axial length. 49
8. The opto-electronic component of claim 7 wherein the second arm has at least a first and a second sidewall disposed therein, the first and the second sidewalls in the second arm cooperating to define therein a groove having a uniform width dimension throughout its length, the uniform groove in the first arm and the uniform groove in the second arm cooperating to define the channel, the channel being rectangular in cross sectional shape over at least a predetermined portion of its axial length.
9. The opto-electronic component of claim 3 wherein each arm has a trough disposed therein, the troughs in the arms cooperating to define a guideway for guiding the fiber therebetween .
10. The opto-electronic component of claim 9 wherein the guideway has an axis therein, the axis of the guideway being offset from the axis of the channel by a predetermined distance.
11. The opto-electronic component of claim 3 wherein basing means comprises a reduced thickness portion in each of me first and the second arms, the reduced thickness portion defining a flexure in each arm which, when each arm is deflected by contact with the member, generates a force on each arm to bias each arm toward the closed position.
12. The opto-electronic component of claim 11 wherein the opto-electronic device is an edge active device.
13. The opto-electronic component of claim 1 1 wherein the opto-electronic device is a surface active device.
14. The opto-electronic component of claim 1 1 wherein the opto-electronic device is a solid state laser. 50
15. The opto-electronic component of claim 1 1 wherein the opto-electronic device is a solid state light responsive diode.
16. The opto-electronic component of claim 14 wherein the opto-electronic device is an edge active device.
17. The opto-electronic component of claim 14 wherein the opto-electronic device is a surface active device.
18. The opto-electronic component of claim 14 wherein the opto-electronic device is a solid state laser.
19. The opto-electronic component of claim 14 wherein the opto-electronic device is a solid state light responsive diode.
20. The opto-electronic component of claim 11 wherein the fiber is a single mode optical fiber.
21. The opto-electronic component of claim 4 wherein the fiber is a single mode optical fiber.
22. The opto7electronic component of claim 3 wherein the fiber is a single mode optical fiber.
23. The component of claim 1 1 wherein the first and the second arms and the foundation are each fabricated from a crystalline material.
24. The opto-electronic component of claim 4 wherein the first and the second arms and the foundation are each fabricated from a crystalline .material. 51
25. The opto-electronic component of claim 3 wherein the first and the second arms and the foundation are each fabricated from a crystalline material.
26. An opto-electronic component comprising, in combination:
a positioning apparatus comprising a first and a second arm, the first arm being mounted to a foundation, the foundation having a pedestal thereon, each arm having at least a first and a second sidewall disposed therein, the first and the second sidewalls cooperating to define a converging groove in each arm,
the arms being arranged in superimposed relationship with the converging grooves therein cooperating to define a channel therebetween that is funnel-like in shape over at least a predetermined portion of its length, the channel having an inlet end and an outlet end and a reference axis extending therethrough,
the arms being arranged such that an optical fiber introduced into the inlet end of the channel with its axis spaced from the reference axis is displacable by contact with at least one of the sidewalls of one of the arms to place a predetermined point on __ end face of the finer into alignment with the reference axis where it is there held by contact with the first and second arms
each of the first and the second arms further including a trough therein, each trough being disposed on an arm a predetermined distance behind the groove in that arm, in the closed position the troughs cooperating to define a guideway for guiding he cylindrical member toward the inlet end of the channel; an.. an opto-electronic device mounted to the pedestal, the opto-electronic device having a reference axis therethrough, the reference axis of the opto-electronic ■ device aligning with the reference axis of the channel.
27. The opto-electronic component of claim 26 wherein the arms are fixed with respect to each other.
28. The opto-electronic component of claim 27 wherein the first and the second arms and the foundation are each fabricated from a crystalline material.
29. The opto-electronic component of claim 27 wherein the opto-electronic device is an edge active device.
30. The opto-electronic component of claim 27 wherein the opto-electronic device is a surface active device.
31. The opto-electronic component of claim 27 wherein the opto-electronic device is a solid state laser.
32. The opto-electronic component of claim 27 wherein the opto-electronic device is a solid state light responsive diode.
33, An opto-electronic component comprising, in combination: a positioning apparatus comprising a first and a second arm, the first arm being mounted to a foundation, the foundation having a pedestal thereon, each arm having at least a first and a second sidewall thereon, the sidewalls in each arm cooperating to define therein a converging groove, the arms being fixed in superimposed relationship with the grooves therein cooperating to define a fully funnel-like channel having a reference axis therethrough, the fully funnel-like channel having an inlet end and an outlet end, the arms being arranged such that an optical fiber introduced into the inlet end of the fully funnel-like channel with its axis spaced from the reference axis is displacable by at least one of the sidewalls to place a predetermined point on an end face of the fiber into alignment with the reference axis where it is there held by contact with the first and second sidewalls of both arms, each of the first and the second arms includes a trough therein, each trough being disposed on an arm a predetermined distance behind the groove in that arm, in the closed position the troughs cooperating to define a guideway for guiding the optical fiber toward the inlet end of the channel; and
an opto-electronic device mounted to the pedestal, the opto-electronic device having a reference axis therethrough, the reference axis of the opto-electronic device aligning with the reference axis of the fully funnel-like channel.
34. The opto-electronic component of claim 33 wherein each of the arms has a major surface thereon, a portion of the major surface connecting the first and the second sidewalls and cooperating to define the groove therein, wherein the converging groove so defined in each arm has a truncated V- shape.
35. The opto-electronic component of claim 33 wherein the opto-electronic device is an edge active device.
36. The opto-electronic component of claim 33 wherein the opto-electronic device is a surface active device.
37. The opto-electronic component of claim 33 wherein the opto-electronic device is a solid state laser. 54
38. The opto-electronic component of claim 33 wherein the opto-electronic device is a solid state light responsive diode.
39. The opto-electronic component of claim 33 wherein the first and the s%cond "arms and the foundation are each fabricated from a crystalline material.
40. An opto-electronic component comprising, in combination: a positioning apparatus comprising a first and a second arm, the first arm being mounted to a foundation, the foundation having a. * pedestal thereon, each arm having at least a first and a second sidewall disposed therein, the first and the second sidewalls cooperating to define a converging groove in each arm, the arms being arranged in superimposed relationship, each arm being movable from a first, closed, position to a second, centering, position,
means for biasing each of the arms with a substantially equal and oppositely directed biasing force toward the first, closed position,
in the closed position the arms cooperating to define a first fully funnel-like channel having a reference axis therethrough, the first funnel -like channel having an inlet end and an outlet end,
each of the arms being arranged such that an optical fiber introduced into the inlet end of the first funnel-like channel with its axis spaced from the reference axis is initially displaceable by contact with at least one of the sidewalls on one of the arms to place a predetermined point on an end face of the fiber into alignment with the reference axis,
the arms being responsive to further axial movement of the fiber through the channel by moving against the bias force toward the centering position to hold the point on the face of the fiber on the reference axis by contact with the first and second sidewalls of both arms; and
an opto-electronic device mounted to the pedestal, the opto-electronic device having a reference axis therethrough, the reference axis of the opto-electronic device aligning with the reference axis of the fully funnel-like channel.
41. The opto-electronic component of claim 40 wherein each of the arms has a major surface thereon, a portion of the major surface connecting the first and the second sidewalls and cooperating to define the groove therein, wherein the converging groove so defined in each arm has a truncated V- shape.
42. The opto-electronic component of claim 41 wherein the biasing means comprises a reduced thickness portion in each of the first ?-nd the second arms, the reduced thickness portion defining a flexure in each arm which, when each arm is deflected by contact with the fiber, generates a restoring force on each arm to bias each arm toward the closed position.
43. The opto-electronic component of claim 40 wherein t« e biasing means comprises a reduced thickness portion in each of the first and the second arms, the reduced thickness portion defining a flexure in each arm which, when each arm is deflected by contact with the fiber, generates a force on each arm to bias each arm toward the closed position.
44. The opto-electronic component of claim 43 wherein the opto-electronic device is an edge active device.
45. The opto-electronic component of claim 43 wherein the opto-electronic device is a surface active device. 0 56
46. The opto-electronic component of claim 43 wherein the opto-electrorjafc device is a solid state laser.
47. The opto-electronic component of claim 43 wherein the opto-electronic device is a solid state light responsive diode.
48. The opto-electronic component of claim 40 wherein the opto-electronic device is an edge active device.
49. The opto-electronic component of claim 40 wherein the opto-electronic device is a surface active device.
50. The opto-electronic component of claim 40 wherein the opto-electronic device is a solid state laser.
51. The opto-electronic component of claim 40 wherein the opto-electronic device is a solid state light responsive diode.
52. The opto-electronic component of claim 51 wherein the fiber is a single mode optical fiber.
53. The opto-electronic component of claim 50 wherein the fiber is Ά single mode optical fiber.
54. The opto-electronic component of claim 49 wherein the fiber is a single mode optical fiber.
55. The opto-electronic component of claim 48 wherein the fiber is a single mode optical fiber.
56. The opto-electronic component of claim 47 wherein the fiber is a single mode optical fiber. 57. The opto-electronic component of claim 46 wherein the fiber is a single mode optical fiber.
58. The opto-electronic component of claim 45 wherein the 5 fiber is a single mode optical fiber.
59. The opto-electrorac comp >ent of claim 44 wherein the fiber is a single mode optical fiber.
0 60. The opϊo-electronic component of claim 43 wherein the fiber is a single mode optical fiber.
61. The opto-electronic component of claim 43 wherein the first and the second arms and the foundation are each
' fabricated from a crystalline material.
62. The opto-electronic component of claim 40 wherein the fiber is a single mode optical fiber.
0 63. The opto-electronic component of claim 40 wherein each of the first and the second arms includes a trough therein, each trough being disposed on an arm a predetermined distance behind the groove in that arm, in the closed position the troughs cooperating to define a guideway for guiding the fiber
25 toward the inlet end of the channel.
64. The opto-electronic component of claim 63 wherein the first and the second arms and the foundation are each fabricated from a crystalline material.
30
65. An opto-electronic component comprising, in combination:
a positioning apparatus comprising a first and a second arm, the first arm being mounted to a foundation, the 35 foundation having a pedestal thereon, the first arm having at 58 least a first aiid a second sidewall, the second arm having a surface thereon,
the first and the second sidewalls cooperating to define a groove in the first arm, the first and the second arms being arranged in superimposed relation and being movable from a first, closed, position to a second, centering, position,
means for biasing each of the arms with a substantially equal and oppositely directed biasing force toward the first, closed position, .
in the closed position the arms cooperating to define a channel having a reference axis therethrough, the channel having an inlet end and an outlet end,
each of the arms being arranged such that an optical fiber introduced into the inlet end of the channel with its axis spaced from the reference axis is initially displaceable by contact with at least one of the sidewalls on the first arm or the surface on the second arm to place a predetermined point on an end face of the fibgr info alignment with the reference axis,
the arms being responsive to further axial movement of the fiber through the channel by moving against the bias force toward the centering position to hold the point on the face of the fiber on the reference axis by contact with the first and second sidewalls on the first arm and the surface on the second arm; and
an opto-electronic device mounted to the pedestal, the opto-electronic device having a reference axis therethrough, the reference aifjs. of the opto-electronic device aligning with the reference aXi& of the channel. oό. The opto-electronic component of claim 65 wherein the groove in the first arm is a converging groove such that the channel is a partially funnel-like channel.
67. The opto-electronic component of claim 65 wherein the groove in the first arm is a uniform width groove such that the channel is rectangular in cross section, each of the sidewalls has an edge thereon, the edges of the sidewalls contacting the fiber.
68. The opto-electronic component of claim 66 wherein the biasing means comprises a reduced thickness portion in each of the first and the second arms, the reduced thickness portion defining a flexure in each arm which, when each arm is deflected by contact with the member, generates a restoring force on each arm to bias each arm toward the closed position.
69. The opto-electronic component of claim 66 wherein the opto-electronic device is an edge active device.
70. The opto-electronic component of claim 66 wherein the opto-electronic device is a surface active device.
71. The opto-electronic component of claim 66 wherein the opto-electronic device is a solid state laser.
72. The opto-electronic component of claim 66 wherein the opto-electronic device is a solid state light responsive diode.
73. The opto-electronic component of claim 66 wherein the first and the second arms and the foundation are each fabricated from a crystalline material.
74. An opto-electronic component co mprising, in combination: 60 a positioning apparatus comprising a first and a second arm, the first arm being mounted to a foundation, the foundation having a pedestal thereon, each one of the arms having at least a first and a second sidewall, the first and the second sidewalls cooperating to define a groove in each of the arms, the first and the second arms being arranged in superimposed relation and being movable from a first, closed, position to a second, centering, position,
means for biasing each of the arms with a substantially equal and oppositely directed biasing force toward the first, closed position,
in the closed position the arms being cooperable to define a channel having a reference axis therethrough, the channel having an inlet end and an outlet end,
each of the arms being arranged such that an optical fiber introduced into the inlet end of the channel with its axis spaced from the reference axis is initially displaceable by contact with at least one of the sid.ewalls on one of the arms to place a predetermined point on an end face of the fiber into alignment with the reference . axis,
the arms being responsive to further axial movement of the fiber through the channel by moving against the bias force toward the centering position to hold the point on the face of the fiber on the reference axis by contact with the first and second sidewalls on each of the arms; and
an opto-electronic device mounted to the pedestal, the opto-electronic device having a reference axis therethrough, the reference axis of the opto-electronic device aligning with the reference axis of the channel. 75. The opto-electronic component of claim 74 wherein the groove in the first and the second arm is a converging groove such that the channel is a fully funnel-like channel.
76. The opto-electronic component of claim 74 wherein the groove in the first and in the second arm is a uniform width groove such that the channel is rectangular in cross section, each of the sidewalls has an edge thereon, the edges of the sidewalls contacting the fiber.
77. The opto-electronic component of claim 76 wherein the biasing means comprises a reduced thickness portion in each of the first and the second arms, the reduced thickness portion defining a flexure in each arm which, wlvn each arm is deflected by contact with the fiber, generates a restoring force on each arm to bias each arm toward the closed position.
78. The opto-electronic component of claim 75 wherein the biasing means comprises a reduced thici ness portion in each of the first and the second arms, the reduced thickness portion defining a flexure in each arm which, when each arm is deflected by contact with the fiber, generates a restoring force on each arm to bias each arm toward the closed position.
79. The opto-electronic component of claim 75 wherein the opto-electronic device is edge active device.
80. The opto-electronic component of claim 75 wherein the opto-electronic device is a surface active device.
81. The opto-electronic component of claim 75 wherein the opto-electronic device is a solid state laser.
82. The opto-electronic component of claim 75 wherein the opto-electronic device is a solid state light responsive diode. 83. Th opto-electronic component of claim 75 wherein the first and seconi arms and the foundation are each fabricated from a crystalline material.
84. An opto-felectronic component comprising, in combination:
a positioning apparatus comprising at least a first and a second arm, the first arm being mounted to a foundation, the foundation having a pedestal thereon, each arm having a seat formed therein,
a lens disposed between the arms, the lens being received in the seat in each arm and centered therebetween; and
an opto-electronic device mouted to the pedestal, the opto-electronic device being aligning with the lens.
EP19900911437 1989-08-02 1990-07-17 Opto-electronic component having a positioned optical fiber associated therewith Withdrawn EP0485426A4 (en)

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US38854889A 1989-08-02 1989-08-02
US388548 1989-08-02

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DE4117449C1 (en) * 1991-05-28 1992-09-17 Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe, De
CA2116668A1 (en) * 1991-08-30 1993-03-18 Melvin Harry Johnson Apparatus for positioning the center of an optical fiber along a predetermined reference axis
JPH06510143A (en) * 1991-08-30 1994-11-10 イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー Optoelectronic component with associated and positioned optical fibers
CA2116667A1 (en) * 1991-08-30 1993-03-18 Melvin Harry Johnson An optical fiber connector having an apparatus for positioning the center of an optical fiber along a predetermined reference axis
CN117150820B (en) * 2023-10-30 2024-03-08 玛斯特轻量化科技(天津)有限公司 Positioning point processing method and device, electronic equipment and storage medium

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AU649621B2 (en) 1994-06-02
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KR920704162A (en) 1992-12-19
IE902781A1 (en) 1991-02-27
EP0485426A4 (en) 1992-09-16
AU6144990A (en) 1991-03-11
JPH04507304A (en) 1992-12-17

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