CA2116669A1 - Opto-electronic component having positioned optical fiber associated therewith - Google Patents

Abstract

An opto-electronic component (20) includes an opto-electronic device (170) of either the edge or the surface (176) active type mounted on a pedestal (174). A fiber (F) is positioned by a positioning device.

Description

l~ lPI~ O9SEPt993 211~66~ P~T/ US 9~ 389 TITLE

OPI O-ELECTRONIC COMPONENT HAVING POSITIONEP OPrlCAL
FIBER ASSOCIATED THEREWITH '~~

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of copending application Serial Number 07/388,548, filed August 2, 1989 (ED-378).

Subject matter disclosed herein is disclosed and claimed in copending application SeIial Number 07/753,277, filed August 30, 1991, titled "Apparatus For Positioning The Center Of An Optical Fiber Al~ng A Predetermined Reference Axis" (ED-377-C), that application being a sontinuation-in-part of copending application Serial Number 07/631,262, filed December 20, 1990 (ED-377-B), which is itself a file wrapper continuation of application Serial Number 07/388,546, filed August 2, 1989 (ED-377) (now abandoned).

Subject matter disclosed herein is disclosed and claimed in copending application Serial Number 07/753,255, f;led August 30, 1991, ~i~ed "An Optical Fiber Connector Having An Apparatuæ
For Positioning The Center Of An Optical Fiber Along A
Prédete~ed E~eference Axis" (ED-377-D), that application being a continuation-in-part of copen~ing application Serial Number 07/628,001, filed December 17,1990 (ED-377-A), which is it~elf a division of application Serial Number 07/388,546, filed August 2, 1989 (ED-377) (now abandoned).

SIJBS~l~p~Eu~lEus~

wo 93/05416 Pcr/usg2/o7389 QOUI~D(lI~lIILINVI~lTlON

Field Of The Invention The present invention relates to a positioning apparatus for positioning the ccnter of an opdcal fibcr or otbcr small dimcnsioncd cylindrical mcn~bcr, such as capillary tubing, along a prcdetcrmined rcfcrcnce axis indepcndently of variations in the outside diamcter of the member.

Description Of The Plior Art Dcvices are known for posidoning an optical fibcr so that the axis of the fibcr is positioncd with rcspect to a rcference axis. A typical cxpedient uscd in such dcvices is a gcnerally V-shapcd groove that is formcd in a substrate matcrial and which scrves as a cradle to acccpt thc fibcr bcing positioncd. Rcprcscntadvc of such dcviccs is that,shown in Unitcd Statcs Patcnt 4,756,591 (~ischer ct al.), wherein a V-groovc is formed in a silicon substratc and an clastomc~ic membcr is biascd against thc fibcr to hold it in thc ~ roovc. Thc groove may be stcpped t~
providc a dccpcr groovc scgm~nt to hold thc jacl~et of thc ffber within thc devicc.
.

Unit,cd Statcs Patcnt 4,756,591 (Sheem) discloses a groovcd silicon substratc having a pair of i~tersecting V-groovcs thercin. A fibcr to bc positioned is disposed in one of thc grooves while a shim is disposed in the other of the groovcs. The shim may talcc the form of a tapered or an cccentric fibcr, which whcn rcspectively slid or rotatcd under thc first fibcr servcs to lift the same to bring the a~cis thereof into alignment with a rcference axis. A cover may be positioned above the substrate to assist in clamping the first fibcr into posidon.

WO g3/05~16 rcr/uss2/073ss -- 3 -- ~
United States Patent 4,802,727 (Stanley) also discloses a positioning arrangement for optical components and w~veguidcs which utilizes a V-grooved structure. 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 frustoconical aperturcs therethrough.

It is believed that single crystalline silicon is tbe material of choice of the devices above mentioned becau~.e of the proclivity of crystalline silicon to be etched along precise crystallographic planes, thus forming precise grooves or structural features by photolithograpbic microfabrication techniques. Etchants exist tbat act upon a selccted crystallographic plane to a differendal degree than upon an adjacent plane, pcrmitting the needed precise control. V-grooves, in particular, can be ctcbed to a controlled width and truncated deptb. Under some conditions V-grooves may be ctched in a sclf-limiting operation. Thc photolitbographic microfabrication process is generally dcscribed by Brodie and Muray, "The Physics of Microfabricadon", Plenum Publishing, Ncw York (1982).

Optical fibers include an inner core ha~ing a prcdctcrmincd index of refraction surrounded by a cladding laycr of a lower indcx. The inner corc is the medium in which tbe optical encrgy is guided, while the cladding layer defines the indcx boundary with the core. Tbc outer diamcter of the fiber may vary in dimension about a predetennined nominal dimcnsion. It has been seen, for example, that two nominally idendcal fibers from the same manufacturer may vary in outside diametrical dimension by as much as plus or minus four (4) micrometers. This ffber to fiber variation in outer diameter makes difficult the accurate positioning of the axis of thc corc of a fiber with respect to a predetermined reference WO 93/05416 PCI`/US92/07389 2116~69 4 axis using a positioning apparatus having a V-grooved structure .

In view of the foregoing it is believed advantageous to make use of the ability of microfabrication techniques to form accurate structures, channels and/or surfaces in ~a crystalline material to construct a positioning apparatus that will accurately position the ccnter 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.

wo 93/05416 2 1 1 6 6 6 9 Pcr/uss2/o738s SUMMARY OF THE INVENTION

The present invention relates to a positioning apparatus for positioning a predetermined point, such as the geometric - center, on the end face of a cylindrical member, such as an optical fiber, along a predetermined reference axis. In a prefcrred case the positioning 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 outlet end and a reference axis extending therethrough. A ~Iber 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 tbere held by contact with the first and second arms. To guide the aber toward the inlet cnd 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 coopcrate to define a guideway.

The arrns having the converging grooves therein may, as is preferred, be movable from a first, closed, position to a second, centering, position. ~he superimposed arms are, in this instance, mounted cantilevered` fashion, to a foundation. Means is provided for biasing each of the arms with a substantially cqual 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 , , ~ ' .

WO 93/05416 PCI`/US92/07389 2 116~69 ~
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 co~verging 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 Iying 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 a groove of an alternate form. Alternately, the present invendon 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 another aspect, the present invention relates to a flber-to-fiber connector formed from confronting pairs of podtioning apparatus. Such a connector is, in the preferred instance, disposed in a housing.

In whatever embodiment rea1ized, 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 and each foundation) is fabricated in mass on a wafer of silicon. The finished` wafers are aligned, wo 93/05~16 2 1 1 6 6 6 9 PCr/usg2/o738s superimposed, and bonded, and each of the resulting positioning apparatus severed from the finished assembly of bonded wafers. Alignment betwcen superimposed wafers is - assured using selected ones of a pl0ality of alignment grooves on each of the wafers and associated precise diameter fibers.

In a most preferred embodiment each of the two arms are divided into two arm segments, or fingers, to compensate for slight misalignments of the grooves.

:

WO 93/05416 PCI`/US92/07389 In a most preferred embodiment each of the two arms are divided into two arm segments, or fingers, to compensate for slight misalignments of the grooves.

wo g3/054-6 Pcr/US92/07389 BRIEF DESCRIPIlON OF T~ DRAW~GS

The invention will be more fully understo,o~-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 one 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 lA is a definitional drawing illustrating the characteristics of a converging groove as that term is used in this application;

Figure 2 is a perspective view of the positioning 20 apparatus of Figure 1 in the fully assembled condition;

Figure 3 is a front elevation view of the assembled positioning ~ppa~atus of Figures 1 and 2, taken along view lines 3-3 in Figure 2;
Figure 4 is a sectional ~iew, in elevation9 of the assembled positioning apparatus of Figure 2, taken along section lines 4-4 in that Figure illustrating the truncated V-groove therein;

~; 30 I Figure 4A is a view generally similar to Figure 4 in which a full V-groove is formed in the positioning apparatus while Pigure 4B is a view generally similar to Figure 4 in which both a full V-groove and a truncated V-groove are formed;
.

WO 93~0S416 PCI`/US92/07389 2116669 lo Figure S is a plan view one of the arms of the positioning apparatus of Figure I illustrating the relationships of the axes of the groove and the guideway therein;

Figures 6A and 6B, 7A and 7B, and 8A an,d~B are diagrammatic elevadonal and end views of tho action of the clips disposed on the arms of the positioning apparatus shown in Figures I 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 I and 2, of another alternate embodiment of a positioning device in accordance with the present invention in which the arms have nonconverging gtooves therein and in which the arms are articulably movable w.th respect to each other along one axis only;

Figures 11 are 12 are sectional views taken along secdon lines 11-11 and 12-12 in Figure 10;
: Pigures 13 and 14 are exp!oded 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 IS are 16 are~sectional views taken along section lines IS-IS and 16-16 in Figure 14;
Figures 17 and 18 are exploded and assembled perspective views, generally similar to Pîgures 1 and 2, of an alternate embodiment of a positioning device in accordance with the present invention in which the arms have converging ,., ,:;

~ -~

WO g3/05416 PCI`/US92/07389 grooves therein and in which the arms are fixed in position with respect to each other;

Figure 19 is an end view taken along view lines 19-19 in 5 Figure 18; f' Figure 20 is a side sectional view, tal~en along view lines 20-20 in Figure 18, illustrating the position of the fiber within the cbannel of the a positioning apparatus in accordance with 10 thc altcrnate cmbodimcnt of the invcntion shown thcrcin;

Figurc 21 is an exploded isometric view of a pair of positioning apparatus as shown in Figure 1 used to form a fibcr-to-fiber connector in accordance with the present 15 invcntion while Figure 22 is an isometric view of the fully assemblcd connector of Figure 21;

Figures 23 and 24 are, respccdvely, a top view in section and a sidc clevadon scction view of a pair of posidoning 20 apparatus i n accordancc the embodiment of the invention as shown in Figure 17 used to form a ~Iber-to-fiber connector in accordance with the present invention;

- Figures 25 and 26 are isometric views of-a housing used 25 for the~-fiber-to-fiber connector shown in Figures 21 and 22 in thc opcn and in the partially closcd positions, rcspectively, while Figure 27 is a section view of the housing of Pigure 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;

, ~ ~

WO g3/05416 PCr/USg2/07389 Figure 29 is a isometric view of an alternate housing for a fiber-to-fiber connector fo,nled of a pair of positioning apparatus;

S Figures 30 and 31 are isometric exploded,~ad assembled views, respectively, illustrating the use of a positioning apparatus in accordance with the present invention to position an optical fiber with respect to the axis of an edge emitting acdve device, in which the device is surface mounted;
Figure 31A 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 are isometric cxploded and assembled views, respectively, generalJy similar to Figures 30 and 31, illustrating the use of a positioning apparatus in in accordance with the prescnt invcntion to position an op~ical fiber with respect to thc axis of a dcvice having active surface device, in ~: which the device is mounted to the end of a positioning apparatus;

Figures 34A through 34F are end views sho~,ving alternate arrangements of movable arms each holding a cylindrical member along at least three contact points in accordance with the present invention;

Figure 35 is a perspective view of a positioning apparatus - 30 having a set of four articulably movable arms in accordance with an alternate embodiment of the present invention for posidoning the center point on the end face of an optical fiber - with respect to a predetermined reference axis, ~he mounting foundation being ommitted;
" ~ ~
~, ~ ~ v ,, ~

WO 93/05416 PCr/US92/07389 Figures 36A and 36B are an isolated perspective views of two of the fingers of the positioning apparatus of Figure 35;

Figure 37 is a side elevation view of the assembled 5 positioning apparatus of Figure 35; ,' - -Figures 38 and 39 are sectional views of the assembledpositioning apparatus of Figure 37, respectively taken along section lines 38-38 and 39-39 in Figure 37;
Figure 40 is a top view of the positioning apparatus of Figure 37 taken along view lines 40-40 therein;

Figure 41 is a side elevational view and Figure 42 is a 15 front elevaticnal view of the assembled positioning apparatus with the fingers holding a fiber in the centering position, the mounting foundation of the positioning apparatus being ommitted;

Figure 43 is a front elevational view, similar to Figure 42 illustrating the situation extant when the finger pairs are misaligned, while Figure 44 is a view illustrating the misaligned finger pairs holding a ~ ger in the centering position; and Figure 45 is a perspective view of an enhanced positioning apparatus that includes the positioning appa~atus of Figure 35 and further includes a clamp rearwardly disposed therefrom, the mounting foundation of the positioning - 30 apparatus being ommitted;

Figure 46 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;

wo s3/0s416 Pcr/uss2/073ss Figure 47 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 48 is an enlarged view of a portion of the mask used for creating a plurality of arms on the wafer 34;

Figures 49A through 49E are schematic representations 10 of the process steps effected during fabrication of the wafer;

Figure S0 is is an enlarged view of a portion of the mask used for creating solder masks on the wafer;

Figure Sl is an enlarged view of a ponion of the mask used for creating foundations on the wafer;

: Figures 52A through 52D are schematic representations - of the steps used to form :a plurality of fiber-to-fiber - 20 ~connectors from superimposed wafers having the arms and foundations thereon.

-,, ~ , , :

WO g3/05416 Pcr/uss2/073ss DETAILED DESCRIPT~QN OF THE D~VENTION

Throughout the following detailed description similar 5 reference numerals refer to similar elements in,~l~Figùres ofthe drawings.

For purposes of a general overview Figures 1 and 2 show a positioning apparatus generally by reference character 20 in 10 accordance with one embodiment of the present invention in an exploded and in a fully assembled condition. Figures 9 through 12 illustrate a positioning apparatus generally indicated by reference character 201 in accordance with another embodiment, while Figures 13 through 16 and Figures 15 17 through 20 illustrate still alternate embodiments 202, 203 respectively, of the positioning apparatus in accordance with the invention. Figure 34A through 34C illustrate yet another alternate embodiment of a positioning apparatus 204 (having three arms). Figures 34D through 45 illustrate yet another 20 alternate embodiment of a positioning apparatus 20S in accordance with the invention in which the upper and lower anns have been subdivided into upper and lower pairs of arm segments, or fingers.
.: - . . .. ..
Z5 Although throughout this applica~ion the positioning `
apparatus is cast in terms of positioning an opdcal ~Iber, it is to be understood that the present invention may be e~fectively utilized wi~h any other member having the form of a small diameter cylindrieal object. By way of example and not - 30 limitatisn, the positioning apparatus in accordance witb the present`invention may be used to position a point disposed, for example, on the end face of a length of microtu~ing or capillary tubing. By small diameîer it is generally meant less than 0.04 inch (one (1) millimeter), but usuàlly less than ~.020 inch.
Moreover, it should be further understood that the term WO g3/05416 PCI'/US92/07389 cylindrical is not to be strictly limited to an object having a completely circular outer conffguration, 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 5 positioning apparatus of the present invention may:be used to position a point disposed, for example, on the cnd face of a polygonal shaped member or an elliptical member.

As will be developed herein, in the preferred instance 10 each positioning apparatus in accordance with this invention is microfabricated from single crystal silicon or another differentially etchable single crystalline material. Crystalline materials are preferred because they permit the accurate formation of the structural features of the positioning 15 apparatus in accordance with the present invention using the process of differential etching.

Any of the positioning apparatus herein disclosed is useful in accurately placing or accurately positioning a center 20 point on a ~lber, typically a central axial point on the end face of the fiber, into alignment with a predetermined reference axis and for maintaining the center point in alignment with the reference axis. As will be developed this reference axis itself may be collinearly aligned with respect to another axis.
By accurately placing or accurately positioning a center point into alignment with a predetermined reference axis it is meant that a point, such as a point on the end face, of the fiber is brought to within a predetermined distance of the reference 30 axis. This distance is, in general, on the order of a few micrometers (i. e., less than about five micrometers) for multi-mode fibers. In the case of a single mode optical fiber, a positioning apparatus in accordance with the present invention is especially adapted for positioning a point of the fiber, such as 35 a point on its end face, to within the precise distance required wo 93/05416 2 1 1 6 6 6 9 Pcr/usg2/o7389 to couple effectively light from the single mode fiber into another fiber or into an opto-electronic device or to couple effectively light from a source, as a solid state laser, into the fiber. This precise distance is e~en less than for multi-mode S fibers for comparable coupling loss- ft The positioning apparatus in accordance with the invendon is also adapted for positioning a point on the end face of a multi-mode fiber with rcspect to a reference axis.
It should understood that the fiber need not be held by the positioning apparatus at the end face of the fiber in order to obtain the accurate posidoning of the point on the end face into alignment with the refercnce axis. In practice, the 15 positioning apparatus contacts the fiber a predetcrmined close distance (on the order of two hundred micromcters) from the end facc. Contacting the fiber at a location rear~ardly from its end face imparts the capability to abut the end face of a fiber with the cnd face of a confronting fiber (as in a conncctor), or 20 to abut the end facc of a fiber with a confronting surface of a dcvice (as in an elcctro-opdcal componcnt).

In some instanccs an enhanced positioning apparatus may be ~provided in order to permit more accurate placing or 25 more accurate positioning of the point on the end face of the fiber into alignment with respect to the predetermined axis. To this end, a second positioning apparatus, spaced rearwardly &om the first positioning apparatus, may be used to function as an alignment clamp for the fiber. This arrangement is seen in 30 Figure 45. Using an enhanced positioning apparatus, the center point on the end face of the fiber may be accurately positioned into alignment with a predetermined refcrence axis such that the center- point lies within a distance of less than one micrometer of the - reference axis.

wo 93/05416 Pcr/uS92/0738s 2116~69 18 If not apparent from the foregoing, it should also be understood that a positioning apparatus in accordance with the present invendon may be used to accurately place or accurately position any other point on the center axis of the 5 ffber into alignment with the predetermined ax~

-o-O-o -As noted, the cylindrical member preferably takes the 10 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 reference axis R. In pracdce the point P
is the geometric center and lies on the axis A of the core C (e. g., 15 Figures 6A and 6B and Flgures 41 and 42) 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 ffber into the positioning apparatus 20. The jacket may comprise more than 20 one layer. As discussed previously, the dimcnsion of the outer diameter D of the cladding 1ayer L of the fiber F may vary from fiber to fiber. Typically this diametrical variation from fiber to fibcr is on the order of three (3) micrometcrs. This situation makes difficult the positioning of the point P along the 25 reference axis R using the positioning devices of the prior art.
--o-O-o-With reference to Figures I and 2 it is seen that the 30 'embodiment of the positioning apparatus 20 there shown includes a first and a second arm 22A, 22B, respectively.
Preferably, each of the arms 22A, 22B is identically formed in a 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 35 apparent, however, that each structural detail of the arm 22A

.
: .

WO g3/05416 2 1 1 6 6 6 9 PCr/USg2/07389 finds a counterpart in the other arm 22B. Accordingly, corresponding reference numerals with the appropriate alphabet suffix will denote corresponding structural details on the arm 22B. If the arms are not substantially identical (as, for 5 example, in the embodiments of Figures 13 thrg~gh 16 and Figure 42) adJustments must be madc to provide the requisite biasing forces to maintain the point P on the reference axis R

Tbe arm 22A includes a base portion 24A having a first 10 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 portion 24A defines the basic dimension of the arm 22A. A
clip generally indicated by the reference charactcr 30A is 15 defined at a first end of the arm 22A. The clip 30A is formed in a relatively thicker abutment portiou 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 providc some feeling for the 20 physical dimensions involYed, 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, 25 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 30 a gencrally 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 35 sidewall 40A has an upper edge 41A thereon. 1~ should be 2116~69 understood that the term "planar" is meant to encompass a surface formed in a single crystal matcrial by etching in which microscopic steps are of necessity produced owing to the lattice structure of the crystal.
~ ~
With reference now to the definitional drawing of Figure lA, the meaning of the term "converging" when applied to a groove in any embodiment of the invention herein disclosed (using the reference characters of Figures I 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 42 and a narrower outlet end 43.
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 Iying therein. The planar surfaces 34 also lie in the refercncc plane RP. The reference axis R extends in the reference plane RP from the inbt end 42 to the the outlet end 43 of the groove 36. Each point on the reference axis R is spaced in the reference~p!ane RP an cqual perpendicular distance from the respecdve upper edges 39, 41 of the sidewalls 38, 40. The distance between the upper edges of the sidewalls and the axis R 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 ~eference plane RP at an angle B that is greater than zero degrecs- but less than ninety degrees. In the reference plane 35 - RP the upper edges 39, 41 of the sidewalls 38, 40 each wo 93/05416 2 1 1 6 6 6 9 PCr/US92/0738g 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 typically 5 the angle B lies in the range from about four (4),~five (5) degrecs. As used herein a "fully funnel-lilce" 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 1 0 surface.

From the foregoing it may be readily understood that a "uniform width" groove is one in which each point on the reference axis R is spaced in the reference plane RP a uniform 15 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 20 or two uniform width groove(s) is termed a "uniform width"
channd~ Such a channel may have a rectangular cross section in a plane perpendicular both to the reference plane and to the reference axis, a$suming no inclination of the sidewalls of the groove.
A tapering groove is one in which the planar sidewalls are perpendicular to the 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 30 '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 embodiment seen in Figures 3 and 4 the groove 36 35 is a converging groove, and more preferably, is a V-groove WO 93/05416 PCr/US92/07389 2116669 22 A~ t truncated by the presence of a third sidewall defined by a ponion 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 5 erected perpendicular to the surface 34A of the~ ~utment: 32A
in a dircction extending toward the major surfacc 26A.

It should be understood that the V-shape of the groove 36A may take altcrnate forms and remain within the 10 contemplation of the invendon. For example, as seen in Figure 4A, the groove 36A may be defined by only the first and second sidewalls 38A, 40A, respcctively, 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 15 full length of the groove 36A.

Figure 4B shows another alternative arrangement in which a truncated V-groovc (defined by the first and sccond sidewalls 38A,~40A, rcspectively, and thc portion of the major 20 surface 26A) cxtends for somc predctormined axial distance whilc a full V-groove (defined by the ftrst and second sidewalls 38A, 40A, respecdve!y) extends for some second predctermincd distancc. Thus, as secn in Figurc 4B, when measured along a dimension line crccted perpcndicular to the 25 surface 34A of thc abutmcnt 32A in a dircction cxtcnding 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 the embodiment of Figures l and 2. For purposes of ease of manufacturability, as will be made clear herein, it is also preferred for the embodiment of Figures 1 and 2 that the 35 groove 36A does not converge throughout the full axial .;
,,,."
~,,, wo 93/05416 2 1 1 6 6 6 9 Pcr/US92/07389 distance through the abutment 32A. Owing to the provision o~
tabs 48A, 48B (Figures I and 5) formed near tbe ends of the abutments 32A, 32B, the sidewalls 38A, 40A defining the groove 36A do not converge throughout the full length of the 5 groove, but define a short uniform width portio~ just past"'tbe converging portion of the groove 36A. The overall axial length of tbe groove 36 (including both the converging and the uniform width ponions) is on tbe order of tbree tenths (0.3) of a millimeter, while the uniform widtb portion of tbe groove I0 occupies an axial length of one tenth (0.1) of a millimeter. As is believed best seen in Pigure 5 the converging and nonconverging portions of the groove 36A have a common axis 50A associated therewith.

Again witb reference to Figure 2, an extended enlargement region 54A having a plan~r surfaco 56A lies on the base portion 24A of tbe arm 22A spaced a predetermined axial distance 58A behind tbe abutment 32A. The distance 58A is on tbe order of one (1) millimeter. The surface 56A is 20 coplanar with the surface 34A. The enlargement 54A is provided with 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 : tbe base portion 24A near the second end thereof. In tbe 25 embodiment shown in Figures 1 and 2 the trough 60A is uniform in depth along its axial length, as measured with respect to 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 30 walls 62A, 64A may be inclined with respect to each other so that the trough 60A may be a full V-shape or a pa~ial 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 35 otherwise conveniently oriented with respect to each other. As WO g3/05416 PCI`/US92/07389 2~16669 24 is believed best seen in Figure 5 the trough 60A and the lead-in 68A bave a common axis 70A. Thc length of the trough 60A
and associated lead-in 68A is on the order of 1.59 millimeter.

Figure S is a plan view of one of tbe arms,æA. In the preferred implementation of the cmbodiment of Figures 1 and 2 the axes 50A, 70A (respectively through the groove 36A and the trougb/lead-in 60A/68A) are offsct a predetermined distance 72 in the reference plane RP (the plane of Figure 5).
Preferably, thc offset 72 is at least one-half the difference between the diameters of the anticipated largest and smallest fibers to be posidoned. As will become clearer herein offsetting the axes 50A, 70A of the structurcs 36A, 60A/68A
facilitatcs thc centering action of the positioning apparatus 20 by insuring that a fiber, as it is introduced into the apparatus 20, is biased to strikc onc of thc sidcwalls 38A, 40A fonning the groove 36A (and analogously, thc sidewalls 38B, 40B
forming the groovc 36B). This insures wall contact with the fi~cr at at Icast t~,vo spaced locations. Howcver, thc presencc of thc offsct 72 neccssitates addidonal manufacturing consideradons, as will be discussed. It should bo noted tbat the force resuldng from biasing the fibcr 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 thc reference axis. ~ -,, :
In tbe assembled condition the 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 ! ~ 30 'the one arm 22A registering with the corresponding groove 36B, trough 60B and lead-in 68B on 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 cnd 94 (Figure 4) and an output 35 end 96 (~;igures 4 and 5). (Notc that if tbc tabs 48 are WO g3/05416 2 1 1 6 ~ 6 9 PCr/USg2/07389 provided, the channel 92 30 defined has a uniform width portion just preceding the outlet end 96 the~cof.) The refsrence axis R extends centrally and axially through the channel 92. The reference axis R lies on the intersecdon of the 5 reference plane RP (which contains tbe conjoine,d surfaces: 34A, 34B) with the plane containing the axcs 50A, 50B of lhe converging grooves 36A, 36B.

The registered troughs 60 and lead-ins 68 cooperate to 10 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 cnlargements ~4A, 54B
(which is the reference plane in the preferrcd case) with the plane containing the axes 70A, 70B (Figure 5) of the 15 trough/lead-in 60A/68A, 60B/1~8B. The axes R and R' both lie in the reference plane RP (th~ planc of the surfaccs 34A, 34B, 56A, 56B) although the axes R and R' are laterally offset with respcct to each other in this refcrencc plane by a predctermined offset distance lO0 (Figure 1:). For a fiber the 20 offset distance 100 is typically on the order of five (5) micrometers.

The inlet cnd 94 of the fully funnel-like channel 92 (best seen in-Pigures 4 and 5) is sized to circumscribc and thereby to 25 accommodate a fibcr 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 30 ' somewhat smaller than the minimum expected outer diameter dimension of the fiber F. In practice, to 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 3S twenty nine (129) micrometers while the smallest expected WO93/05416 PCl/US92/07389 2116~6~ 26 `

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 5 that the guideway 98 so formed by the registero~roughs: 60A, 60B is sized to accommodatc a fiber F whose cladding layer L
has the largest expected outer diameter dimension. Despite its dimension with respect to tbe ~Ibcr, the guideway 98 assists in the insertion of a fibcr into the positioning apparatus 20 and is 10 advantageous in this regard.

In the embodiment shown in Pigures 1 through 5 the surfaces 34A, 34B on the respcctive arms 22A? 22B, respecdvcly, are, when in a first, closcd, position, either in 15 contact with eacb other or, if desired, within a predetcrmined close distance to each other. For opdcal fibcrs tbe predctermined closc distance is typically on the order of five (5) to twenty-five (25) micrometers. In this cmbodiment the planar surfaces 34A, 34B on the abutments 32A, 32B of the 20 clips 30A, 30B are not securcd to each o~her and may move to a second, centering, position, as will be described. The planar surfaces 56A, 56B on the respecdve arms 22A, 22B are secured ~to cach other by any convenient means of attachment, as by fusing or soldering. It should be understood that any other 25 mechanical securing expedient may be used to attach or otherwise hold together the surfaces 56A, 56B to each other.

The positioning appara~tus 20 further includes a mounting foundadon 74 (Pigurcs 1 and 2). The mounting foundation 74 30 is provided with a planar attachment surface 76 thereon. A
step 78 in the mounting foundation 74 serves to 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 35 soldering, to- the planar attachment surface 76 on the , :
:~, foundation 74. Of course, it should be again understood that any alternative mechanical attachment cxpedicnt may be used to attach or otherwise hold together tbe second major surface of the arm to the foundation 74.
Although the second surface 82 of tbe foundation is shown in the Figures as being gcncrally planar in the preferred case, it should be understood that this surface 82 may take any desired conffguration. As will be more fully appreciated 10 herdn, so long as the opposite surface 28A of the arm 22A
affixed to the foundation 74 is, at least in the region of the clips 30A, spaced at least a predetermined clearance distance 80 from the second surface 82 (assuming the surface 82 is parallel to tbe surface 76), the movement of thc clip on the arm 22A
15 attached to the foundation (in the drawingst the c1ip 30A) to be described will not be impeded.

When assembled, the clips 30A, 30B disposed at the ends of the arms 22A, 22B, rcspectivcly, arc supported in a 20 candlevered fashion from thc conjoincd enlargements 54A, 54B
~at the opposite ends of the ums. The arms 22A, 22B are rigid in x-z plane, as defincd by the coordinate a~ccs shown in Figure 1. Moreover, the relativcly thin dimension of the central region 25A, 25B of the base portion 24A, 24B of ~c arms 22A, 25 22B axially intermediatc the respectivc abutments 32A, 32B
and the en1argements 54A, 54B acts as a flexure and permits each arm 22 to flex, springboard fashion, in the directions of thc arrows 88 in the y-z plane. As used herdn it should thus be appreciated that a flcxure is a spring member that is rigid in 30 lonc plane and is constrained to flcx in thc orthogonal plane.

It should furthcr be appreciated that when a clip 30A, 30B is deflccted in its corresponding respective direction 88A, 88B, the resiliency of thc thinncr ccntral region 25A, 25B of the 35 ~base 24A, 24B~, acdng ~as a flcxure, dcfines means for biasing ." , , ~,, the clips 30A, 30B toward the first, closcd, position. The biasing force acts on the clip 30A, 30B in a direction shown by the arrows 90A, 90B, counter to the direction of motion 88A, 88B of the arms. The biasing forces must be substantially 5 cqual and in opposite dircctions. In gcncral? w,~atever the numbcr of arms uscd in thc positioning apparatus, the force on each arm passes tbrough tbe refercnce a~cis and the sum of forces when in tbc centcring position substantially cquals zero.
Biasing mcans employing thc thinner ccntral region of the base 10 24 as a flexure (as shown in the Fig0cs 1 to 4) is prefcrrcd for all disclosed embodiments, because when implemented in a single crystal material using a microfabrication technique precise control of the biasing forces is able to be attained.
Typically the bias force on each arm is on the order of five (S) 1 5 grams.

lt should bc understood that any other convenient mecbanism may bc used to define the means for biasing the arms and the clips 30 tbercon toward the closed position so 20 long as the force on each arm passcs through thc reference axis and the sum of forccs on d~e anns when they are in the centering posidon is substantially cqual to zero. Whatever form of Wasing mcans is sclccted thc bias force must increase with deflecdon of the arm.

-o-O-o-Having defined the structure of the positioning apparatus 20 of the embodiment of Figures 1 and 2, the operadon thereof 30 in posidoning a point P on the center axis and on the end face E
of an optical fiber F along a predetermined reference axis R
may be readily understood in connection with Figures S
through 7.

~'VO 93/05416 2 1 1 6 6 6 9 PCI`/US92/07389 In operation the fiber F is inscrted into the positioning apparatus 20 in the direction of the arrow 102 (Figure 6A).
The lead-in portions 68A, 68B (Figure 1) coopcrate to guide the fiber F into the guideway 98 (Figurc 2) defined by the 5 registered troughs 60A, 60B in the enlargements~A, S4B
(Pigure 1). Because the axis R' of tbc guideway 98 is offset from the axis R of the fully funnel shaped channel 92 the guideway 98 sen~es to guide the face E of the fiber F toward the inlet end 94 of the channel 92 at a predetennined azimuth 10 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, or moved, through contact with at least one of the sidewalls 38A or 38B, 40A or 40B (or 15 portions of the major surface 26A, 26B, if these are used to dcffnc tbe groovcs 36A, 36B, as in Figurc 4) on one of the clips 30A, 30B, respectively, to the cxtent necessary to move a predetermined point P on an end facc E of the fiber F toward alignment with the refercnce axis R.
At some point on the path of axial insertion of the fiber F
into the channel 92, as the cnd E of thc fiber F movcs toward the outlet end 96, the outer diameter of thc cladding layer L of thc fibcr F exceeds thc dimension of thc channel 92. Thc arms 25 22A, 22B respond to a forcc 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 Was 30 force acting in the directions 90A, 90B generated by the flexing of the arms 22A, 22B, to separate the surfaces 34A, 34B
- thereon. However, this movement of the arms 22A, 22B from the first toward the second position positions the point P on the end face E of the fiber F on the reference axis R. The end face E
3S of the fiber F thus exits through the outlet end 96 of the fully WO g3/05416 PCI`/US92/07389 ,~ .~

funnel shaped channel 92 with thc point P prccisely aligned with (i.e., within one micrometer of) the referencc axis R, as is shown in Figures 8A, 8B. The fiber F is held in this position by contact with the sidewalls 38A, 38B, 40A, and 40B.
If the tabs 48A, 48B are formed on tbc abutmcnts 32A, 32B these tabs cooperate to define a passage of uniform width along its axial length that communicates with the outlet of the funnel-like charnel. The fiber F passes through and emerges 10 from such a conduit with the point P on the end face of the fiber still along the reference axis R.

It should be noted that the movement of the arms could be other than the flcxing thcrcof as dcscribed herctofore. It 15 therefore lies within the contcmplation of this invcntion to have thc arms movc in any other manner, as, for c~tamplc, by any forrn of pinned or jointcd (articulated) motion.

-o-O-o-With rcference now to Figures 9 through 12 an altcrnate embodiment of the positioning apparatus 20l in accordance with the prescnt invention is shown. In this embodimcnt the arms 221 are, similar to the embodiment earlia discussed, 25 articulably movable in cantilcvcrcd fashion with respect to each othcr against thc bias of the flcxurc dcfined by the central portion 2~l thcreof. However, the grooves 361 formed in the arms 22l are not converging grooves, but arc uniform width grooves. Accordingly thc channel 921 formed by the 30 cooperativc association of the arms 22l when superimposcd one on the other is a uniform width channel. The maximum dimcnsion of such a channel 92l in the planc perpendicular to the rcfercnce R is less than the outside diarncta of the smallest anticipated fîber F.

~VO 93/05416 2 1 1 6 6 6 9 PCI`/US92/07389 A further modification to the positioning apparatus 201 may be seen from Figure 12. It is first noted that the planar walls 621, 641 of the troughs 601 are parallel, rather than inclined with respcct to each other. Moreo~er, the offset 100 S between the axes R and R' lies in the vcrtical p~an~, that is, in the plane containing the a~ces 701 of the troughs 601, as opposed to being offset laterally (i.e., in the plane containing the surfaces 561). The lead-in portions 681A, 681B are ommitted here but may be provided.
In operation, a fiber F is inserted into the positioning apparatus 201 and guided by the passage 981 defined by the registered troughs 601A, 601B. Because the axis R' of the passage 981 is vertically offset from the axis R of the channel 15 921 the surface 261B of the arm 221B bounding the passage 981 serves to guide the fiber F toward the inlet end 941 of the channel 921. Thc fiber F enters the channel 921 and contacts with thc edgcs of the sidewalls 381A, 381B, 401A and 401B.
- Due to the sizing of the grooves 361A, 361B the fiber F does not 20 touch the major surface 261A, 261B of the arms 221A, 221B, respectively. Thc fiber may bc chamfered or tapcrcd or a mechanical de~ricc may be used to facilitate insertion of thc aber into the channel 921.
.. . .
.
Since the fiber F exceeds thc dimension of the channcl 921 the clips 301A, 301B are displaced from the ~lrst, closed, position toward a second, ccntering, position. This movcmcnt of the clips 301A, 301B maintains the point P on the end face E
of the fiber F on the refcrcnce axis R. The end face E of the fiber F thus exits through the outlet cnd 961 of the channcl 921 with thc point P prcciscly aligned on thc refcrence axis R. The ~iber F is hcld in this position by contact with the edges of the sidewalls 381A, 381B, 401A, and 401B, as indicated by the character LC.
, :

WO 93/05416 PCI`/US92/07389 2116669 32 `' - O -O-o -The embodiment of the positioning apparatus 201 shown in Figures 9 to 12 can be further modified, as seen by the S positioning apparatus 202 shown in Figures 13 ,t~16. In this modification, the arm 222B differs from those shown earlier in that no groove is provided therein (Figurc lS). In this embodiment, if the groovc is a convcrging groove, a partially funncl-like channel is de~lned. The fiber F is guided by contact 10 against the major surface 262B and hdd in position on the refercnce axis R by contact with the major surface 262B and the cdges of the sidewalls 382A, 382B, again as indicated by the character LC.

1 5 -o-0-o-Figurcs 17 and 18 arc cxploded and asscmblcd perspective views, generally similar to Figurcs 1 and 2, of anothcr altcrnate embodimcnt of a positioning apparatus 203 in accordancc with thc present invcndon whilc Figure 19 shows thc end view thereof. In this embodimcnt, instead of thc arms - being articulably movablc as dcscribed carlicr, thc arms are fixed relative to each otha. Each of the arms 223A 3nd 223B
has a converging groove thercin and the channel 923 formed by the cooperative association of the arms 223 when superimposed one on dle other is fully funnel-like in form.
The channel 923 defines a minimum dimension in the plane perpcndicular to the referenc~e 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 203 and guided through the passage 983 toward the inlet end 943 of the channel 923. The fiber F enters the funnel-like channel 923 and is guided by contact with one or more of 35 tbe sidewalls 383~, 383B, 403A and 403B and/or major wo 93/05416 2 1 1 6 6 6 9 Pcr/Usg2/0~38g surfaces 263A, 263B to place the point P of the fiber F on the axis R. However, sincc the arms 223 are fixed with respect to each other, the fiber F can only advance wilhin the channel 923 to the axial location where the outer diameter of the fiber F
5 equals the local dimension of the channel 923. ,~-this~axial locadon within the channel thc 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 383A, 383B, 403A, and 403B. The dimension of the channel is such that the lO fiber is not able to contact the major surfaces of the arms 223 when it is held along the reference axis R. Figure 20 illustrates the fiber as the same is held within the channel 923 The axial spacing 104 between the end face E of the fiber F and the outlet end 963 of the channel 923 varies, dependent upon the 15 outer diameter dimcnsion of the fiber F.

-o-O-o-The positioning apparatus 20, 201, 202 and 203 in 20 accordance with any of the above-described embodiments of the invention may be used in a ~rariety of applications which require the precise posidoning of a point P on the end face E of a ffber F along a refercnce axis R.

In Figurcs 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 12~. In this arrangement the apparatus 20-1, 20-2 are confrontationally disposed w;th respect to the other so that the outlet cnds 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 pla~nar attachment surface 76. Each WO 93/05416 ' ' PCI'/US92/07389 positioning apparatus 20-1, 20-2 is mounted to its respective attachment surface 76.

The ~lbers F-l and F-2 to bc connected are inserted into 5 the lead-ins 68 of the respective positioning a~paratus~ 20-1, 20-2. Each positioning apparatus 20-1, 20-2, acting in thc manner described above, serves to place the point P on the end face E, of the respecdve fibcr F-l or F-2 along the collinearly disposed axes R. The fibers F-l, F-2 are inserted in to the 10 respcctive apparatus 2.0-1, 20-2 until thc cnd faces E on each ber abut. The cnds E of the fibers F-l, 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 ultraviolct curing adhesive such Ihat manufactured 15 and sold by Electro-Lite Corporation, Danbury, Connecticut as number 82001ELC4480, may be used.

It should be understood that the fiber-to-fiber connector may be implemcnted using any of thc othcr of the abo~re-20 discusscd alternadve cmbodîmonts 201, 202, and 203 of theposidoning apparatus. In thc cvcnt a pair positioning apparatus 203 as shown in Figure 17 is used~ (see Figures 23 and 24), the con&onting cnds of thc positioning apparatus 203-1, 203-2 are preferably abu~ted and secured, or the pair of 2S positioning- apparatus formed integrally with each other. The spacing lZ2 bctwcen the cnd faces E of thc fibers F-l, F-2 is, in this cmbodimcnt, dcfined by the sum of the distances 104-1, 104-2. The spacing 122 is filled with an index matching matcrial, such as the adhesiYe defined above. To this cnd, an 30 access port 124 is provided to permit the introduction of the index matching matcrial into the region between the cohfronting end face of the fibers F-l, F-2.

-~ Prior to insenion into the posidoning apparatus (of 35 whatcver form) it should be understood that the jacket ~
~, : -wo 93/~5416 2 1 1 6 ~ 6 9 Pcr/usg2/o7389 (Figure 29) of the fiber F is stripped in its entircty a predetermined distance from the frec cnd tbercof. The exposed portion of tbe fiber is cleaned with alcohol. The fiber is cleaved to form the end face E. If desired the end face E may 5 be ground into a convex shape to yield a point,p~be lenscd.

-o-O-o If desired thc fiber-to-fiber connector 120 may be 10 disposed in a suitable housing !30 (Figure 25). The preferred form of the housing 130 is generally similar to that disclosed in United States Patent 4,784,456 (Smith), assigned to the assignee of the prcsent invcntion. This patent is hereby incorporated by rcference herein. The housing 130 includes a 15 base 132 and a covcr 134. ~he base 132 is, in all cases, provided with a reccss 136 that is sized to closely receive the connector 120. 1f the connector 120 is realized using any form of the positioning apparatus that articulates, the cover 134 must be providcd wi* a corrcsponding recess 138 located so 20 as to permit the articuladng motion of the arms of positioning apparatus used to form the conncctor. If tbe connector 120 is real1zed using the form of the positioning apparatus shown in Figuros 23 and 24, the recess 138 need not be provided. Such a housing 130 is shown in Figure 28.
The cover 134 is scgmented into three sections, 140A, 140B, 140C, each which is binged to the base 132. The base 132 has, adjaccnt to cach end of the rcccss 136, V-shaped groovcd rcgions 142A, 142B. The top end secdons 140A, 140B
30 each contain respecdve generally tapered lands 143A, 143B.
Each of the lands has serrations 145A, 145B respectively thcreon.

- In use a conncctor is inscrtcd in ~c reccss 136 of the 35 housing 130. It is thcrc hcld in placc by friction but may bc ~, ' ~ ' ~:

WO g3/05416 PCI'/US92/07389 2I 16~69 36 otherwise secured if desired. The central section 140C of the co~rer may then be closed, if desired. An opdcal fiber having a predetermined length of its jacket J stripped and cleaned, is inserted through one of the V-shaped grooved regions 142A, 5 142B to dispose the stripped end of the fiber i~t~the connector 120. Thc grooved region serves to properly odent and position the fiber with respect to the connector 120 in the recess 136.
The associated top end section 140A, 140B, as the case may be, is then closed and latched to the corresponding portion of the 10 base 132 (Figwe 25, with thc fiber ommitted for clarity).
When the top is secured to the base the serrations 145 act against 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 analogous 15 manner. If not already done so, the ccntral secdon 140C of the co~er is then closed. The housing 130 is preferably formed by injection molding.

As seen in Figure 29, in anothcr forn the housing 130 20 may be implemented using a mass 160 of index matching matcrial, such as that identiffed above. The mass 160 extends over both the connector 120 (to embed the same therein) and some predetermined portion of the jaclcets J of the fibers F-l, F-2.

-o-O-o-The reference axis R on which the point P of the fiber F is posidoned may itself extend collinearly with the axis X of any 30 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 ffber 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 35 fiber F along an axis X of a device 170. The de~rice 170 may, WO g3/05416 2 1 1 6 6 6 9 Pcr/usg2/o738g 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 deviccs or surfacc active devices. Although in the discussion tbat follows the reference 5 character 20 is used to indicate the positioning,~paratusj- it should be understood that any one of tbe cmbodiments of the positioning apparatus 201, 202 or 203 heretoforo described may also used.

When used in connection with an edgc active dc~ice 170 the arrangement in Figures 30 and 31 is preferred. In this arrangement the foundation 74 is axially cxtcnded to deffne a pedestal 174 at the axial end thereof. The upper surface 176 of the pedestal 174 defines a planar attachment surface. The 15 surface 176 is spaced a predetermined distance above thc 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 thc reference axis R are collincar.
With the axes R and X collincar, thc positioning of the point P
20 on the fiber F along the axis R will automatically position that point P in the same rdationship with the axis X. Thc device 170 must be accurately mounted on the surface 176 so that its axis X is collinearly aligned with the axis R.

To mount the device 1;0 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 micropositioning apparatus, such as a vacuum !~ 30 I 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 a surface acti~e device, as seen in 35 Figures 32 and 33, the activc surface of the device 170 is WO 93/05416 PCI`/US92/07389 2116~69 38 secured to 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 posidoning apparatus 20. The surface 176 of tbe pedestal 174 S is relieved to avoid obstrucdon between tbe acti~ region.of the device 170 and the end face E of tbe fiber F.

It should also be appreciated, as is illustrated in Figure 31A, that the positioning apparatus in accordance with any one 1 0 of tbe cmbodiments heretofore described may be configured to accurately posidon a lens, such as a ball or a rod lens L, with respect to the axis X 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 3IS in the clips 15 30 thereof sized to accept the lens L.

-o-O-o -In addition to the various embodiments of the two-armed 20 configurations for the positioning apparatus 20, 201, 202 and 203 of the present invcndon previously disclosed, it lics within the contempladon of this invention for a positioning apparatus in accordance with this invention to cxhibit more than two arms 22.
In this regard Figures 34A to 34C genaally illustrate a positioning apparatus 204 having three arms 22A, 22B and 22C.

Figures 34D through 34F generally illustrate a 30 Ipositioning apparatus 205 having four arms 22A, 22B, 22C and 22D. A detailed description of an embodiment of a four armed positioning apparatus 205 is set forth hereinafter.

The extension to even greater number of arms would be 35 readily apparent to those skilled in the art.

wo g3/0s4l6 2 1 1 6 6 6 9 PCI'/US92/07389 Generally speaking, in Figure 34A each the arms are conffgured similar to the form of the arms discussed above.
The arms may, if desired carry a groove, although it should be 5 understood that such is not required. In Figure3~34B and---`34E
the arms are configured from rods. Although tbe rods shown as round in cross section it sbould be understood that they can have any desired alternate cross section. In Figures 34C and 34F the arms are configured in a generally planar bar form. As 10 will be fully set forth herein, in Figure 34D the four arms may be formed by sawing the upper and lower arms (indicated by the characters 22A, 22B in Figures l to 4) along a cut line extending perpendicular to the major surfaces 26 and 28 of each of the arms, thereby to define upper and lower pairs of 15 arm segments, or "fingersn. As used in this application, the term "fingers" is to be understood to be the structures defined when an "armn, as that term has been used herein, is subdivided into two axially elongated segments.

20 - However configured the arms are shown in Figures 34A
~hrough 34F as angularly juxtaposed in a surrounding relationship to the channel 92 defined their cooperative association. Similar to the situation described heretofore the resiliency of tbe arms defines the biasing means which urge 25 the arms toward the closed posidon. However, it should be understood that the biasing means may be other vise defined, so long as the force on each arm passes through the reference axis and the sum of forces on the anns when they are in the centering position is substantially equal to zero. Whatever 30 form of biasing means is selected the bias force must increase with deflection of the arm. The arms act against the ffber F
inserted into the channel along the various lines of contact LC
illustrated in Figure 34 to maintain the predetermined point on - the fiber on the reference axis R.

-0-0-o-In practice, during fabrication of the posi~doning device misalignment may somctimes occur between the first and S second arm in the arm pair (~:igure 1). As a rcs,~,- in use, Ihe fiber may be supported by only two diametrically opposed sidewalls on the first and second arms (see Figure 43). Thus, the fiber may not be positioned to lie along the refcrence axis.

A positioning apparatus 205 in accordance with the embodiment of the invention shown in Figures 35 through 40 is believed able to avoid this result. With reference to these Figures it is seen that each arm (225A, 225B, Figure 35) is itself longitudinally slit along slit lines 215 thereby to define a set of 15 four fingers, 225-1, 225-2, 225-3, 225-4, arranged into a first, upper, pair of fingers (225-1, 225-2) and second, lower, pair of finger pairs (225-3, 225-4).

As shown in Flgure 36A, in a manner generally similar to 20 :the eu~or discusscd embodiments, each finger in the set includes a~ baso portion 245 having a first major surface 265 and a second, opposed, major surfacc 285. The base portion 24S ~extends alopg the full length of each finger and the dimension o f the central region 255 of the base portion 245 défines the~basic dimension of each ~Inger.

A clip generally indicated by the reference character 305 is defined at a ~lrst end of each finger 225. The clip 305 is formed in a relatively thicker abutment portion 32S that lies on I the ~Irst surface 265 of each finger 225. The abutment 325 has a planar surface 345 thereon that preferably lies parallel to the first major surface 265. Again, to provide some feeling for the physical dimensions involved, the finger 225 has an overall : length dimension on the order of twenty four hundred (2400) ~ 35 micrometers and a width on the order of cight hundred (800) ,~ , wo 93/05~16 2 1 1 6 6 6 9 PCr/USg2/07389 micrometers. In the central region 255 each finger 225 has a thiclcness dimension on the order of one hundred (100) micrometers.

Each abutment 325 includes a planar side,~kall 335 that cxtends in an inclined manncr (at an angle of 54.74) from the pcrpcndicular to the major surface 265 of cach finger. The sidewalls 335 in the fingers of the first pair 225-l and 225-2 cooperate to define a uniform width groove 365 while the sidewalls 335 in thc fingers in the other, mating, finger pair 225-3 and 2254 also cooperate to define a similar uniform width groove 365.

Each finger has, at the end opposite the abutment 325, an I 5 cnlargement generally indicated by thc refcrcnce character 54S. The cnlargement has abutments 555A and 55SB thereon.
Each abutment 55SA is provided with a wall 625 that cooperates with the corrcsponding wall 625 on the other finger in the pair and witb a ponion of the major surface 265 of the - 20 base portion 245 near the second end thercof to form a nonconvergilng, uniform width, truncated V-shapcd trough 605.
In the embodiment shown in Figures 35 and 36 the trough 6~5 - is unifo~m in depth along its axial length, as measured with - - respect to a dimension line erected perpendicular to thesurface 565A extending toward the major surface 26S. The trough has an axis 705 cxtending ccntrally and axially therethrough. The trough 605 is wider than the width dimension of the groove 365. In a more preferred arrangement the trough 605 communicates with a converging lead-in 685 defined by the cooperative association of surfaces 695 provided on each abutment 555A on the fingers in the pair.

A most preferred arrangement has two angled surfaces at each lead-in corner of cach abutment, as shown in Figure 36B.
Abutmcnts 325 looked similar to the abutments 555A before à
, wo 93/05416 Pcr/uss2/0738s cut is made to form the linear front edges of the abutments 32S, as shown in Figure 36B. As will become clearer herein, the surfaces 565A on the abutments S55A of opposed finger pairs are joined, by any convenient means of attachment, as by 5 fusing or soldering. In Figure 36B the lateral sy~ccs of-the abutments 325 and the abutments 555A are ramped or inclined with respect to the major surfaces 265.

The surface 565B on the the abutment S5SB depending 10 from the surface 285 is spaced a predetermined distance 805 from the surface 285 of the ffnger 225. As will also become clearer herein, the abutment 555B thereby functions as a standoff to space the finger away from a foundation or slab on which it is mounted.
In the assembled condition, best shown in Figures 35 and Figures 37 through 40, co~responding fingers in each pair are disposed in superimposed relationship one above the other, - with the groove 365 and the trough 605 cooperatively defined 20 by the fingers in one pair registering with the corresponding groove and trough formed by the cooperative action of the fingers in the other pair.

The grooves 365 formed by the cooperative action of the 25 fingers in each pair are themselves registered and thus cooperate to define a channel 925 (Figures 35 and 39). The channel 925 has an h~put end 945 and an output end 965. The ~eference axis R extends centrally and axially through the channel 925. Preferably, the reference axis R lies in a reference 30 plane RPl containing the surfaces 565A on each finger 225 (see Figure 38). Most preferably, the reference axis R also lies in a second reference plane RP2 (Pigure 39) containing the slit lines 215 defining each pair of fingers in the finger set. It should be understood that manufacturing tolerances can result in slight 35 misa1ignment of axis R with respect to the reference plane RP2.

~, wo 93/05416 2 1 1 6 6 6 9 Pcr/usg2/o738g The consequences of such a misalignment will be discussed more fully hereafter.

The registered troughs 605 (and lead-ins 685, if present) cooperate to define a guideway 985 (Figures 361~nd 38).- The axis R' through thc guideway 985 lies in the plane containing the conjoined surfaces 56SA of the abutments SSSA (see Figure 38). The plane RP2 (Figure 38) contains the axes of the troughs.
The axes R and R' both lie in the reference plane RPI (the plane of the surfaces 565A) and should preferably both lie in the reference plane RP2.

In the embodiment shown in Figures 35 through 40 the surfaces 345 on opposed corresponding fingers in cach pair are, when in a first, closed, position, cither in contact with each other or may, as prcfcrrcd, bc within a prcdetermined close distance to each other to insure they will not be affected in joining opcrations. For opdcal fibers the predetermined close distance is typically on the order of one (1) to two (2) micrometcrs. The planar surfaces 34 are not secured to each other and thus may move to a second, centering, position, as will be described.

As secn in Fig0e 35 the positioning apparatus 205 further includes, in the preferred instance, a mounting slab 745 having a planar attachment surface 765 thereon. The surface 56SB of the abutment 555B on each ffnger 225-3, 225-4 is secured, as by fusing or soldering, to the planar attachment surface 765 on the slab 745. Owing to the presence of the - 30 abutment SSSB, the surfaces 285 on the fingers 225-3, 2254 of the lower pair are spaced the distance 805 from the attachment surface 76S. It should be understood that the abutment SS5B
may be omitted, and the lower fingers 225-3, 225-4 may be mounted to a foundation ?4having a step 82thereon similar to that shown in Pigure 1, in order to provide the clearance '~;

WO 93/05416 PCr/US92/07389 distance 80S nccessary to pcrmit the movement of the lower fingers in each pair. The fingers 22S-1, 225-2 in the upper pair of fingers may also be secured, as by fusing or soldering, to the planar attachment surface 765 on a second slab 74S The 5 sccond slab 74S is shovn in outline in Figure 35,.' -When assembled, as shown in Figure 35, the clips 305disposed at the ends of tbe fingers 225 are supported in a cantilevered fashion from the conjoined enlargements 54S at 10 the opposite ends of the fingers. Each of the fingers 225 is relatively rigid in x-z plane, as defined by the coordinate axes shown in Figure 35. Moreover, the relatively thin dimension of the central region 255 of the base portion 245 of each finger 225 axially intermediate the respective abutments 325 and the 15 enlargcments 545 acts as a flexure and permits the clips 305 at the cnd of each finger 225 to flex, springboard fashion, in the directions of the arrows 885 in the y-z plane. Again, as the tcrm is used herein, a flexure is a spring member that is relatively rigid in one plane and is constrained to flcx in the 20 orthogonal plane.

It should furtber be appreciated that when a clip 305 is deflectcd in its corresponding respective direction 885 the resiliency of the thinner central region 255 of the base 245, ~- 25 acting as a flexure, defines means for biasing the fingers 225 and the clips 305 thereon toward the first, closed, position. The biasing force acts on each clip 305 in a direction shown by the arrows goS counter to the biasing directions 885. It should be understood that any other convenient mechanism may be used 30 to provide the means for biasing the clips 305 toward the closed position. The biasing forces must be substantially equal and in opposite dircctions. Biasing means employing the thinner central region 255 of the base 245 as a flexure is, howcver, again preferred because when implemented in a 35 single crystal material using a microfabrication technique : ~

wo 93/05416 2 1 1 ~ 6 6 9 Pcr/us92/o7389 prccise control of the biasing forces is ablc to be attaincd.
Typically the bias forcc on cach finger is on the order of twenty (20) grams.

O o 0 Having deffncd the structure of the positioning apparatus 205 in accordancc with this embodiment of the invention, the opcradon thcrcof in positioning a point P on thc ccnter axis and 10 on thc cnd face E of an opdcal fibcr F along a predetermincd rcferencc axis R may bc rcadily understood in connccdon with Figurcs 38 through 43. As mentioned earlier, and as is clearly visiblc in Figurc 41, wbcn positioning thc point P into alignment with thc rcferencc axis R thc positioning apparatus 15 actually contacts tbe fib at contact points Iying a close ~distance from~the end faco E.

Assuming that the reference ~axis R (Figure 39) of the ' channel 92 aligns ~with both the ~Irst and ~second rcfcrence 20 ~planos~ , RP2~;~(Figurc 38),~ tho` operation of the posidoning ' ~ice 205 is substantially ~identical ~with the operation of the positioning deYico shown and discussed earIier in connecdon Pigure 6 ~rough 8.~ I~us, the fiber F is ioscrtcd into the positioning~ appuatus 20S in ^thé direcdon of -the arrow 1025 (Figures 37, 41).~ The ~ F is insertcd into the guideway 985 defined by"thé rcgistered troughs 605. The fiber F enters the chanrlel 925 and is initially displaced, or moved, through contact with 'at least one of ~the sidewalls 33S or portions of the major surface 265 used to define the groo~rés 365 on one of the - 30 clips~ 305 to the extent necessary to accurately place a prcdetennined point P on an end face E of the ffber F toward - ~ alignment with the reference axis R.

' Since the ~outer diameter of the cladding layer L, shown 95~ ~on Figures 41 and 42, of the~ fiber F exceeds the dimension of ~,- , ~ , . ,. ~, ~,, WO 93/05416 PCI`/US92/07389 2116~G9 46 the channel 765 formed by the sidewalls the fingers 225 respond to a deflecting force in the directions 88S imposed thereon by the fiber F by displacing from the first, closed, position (shown in Pigure 39) toward a second, centering, 5 posidon shown in Figures 42 and 43. In the c,cn~ering position the clips 305 open against the bias forcc acting in the dircctions gos generated by the flexing of the fingcrs 225 to separate the surfaces 345 thereon. This movement of the finger 225 from the first toward the second position accurately positions the 10 point P on the end facc E of the fibcr F in alignment with the reference axis R. The end face E of the fiber F thus exits through the outlet end 965 of the channel 925 with the point P
accurately positioned in alignment with the reference axis R, as is shown in Figures 34 and 42. The fibcr F is held in this 15 position by contact with the sidewalls 335.

-o-O-o-As alluded to earlier, in some instances, owing dther to 20 misalignment between arms (before they arc slit to form finger pairs), misalignment between the slit lines 215 in each finger : pair and the desired location of the slit lines on each arm, mismatches of finger thiclcness, and/or mismatches of finger widths, the assembled position of the supcrimposed finger 25 pairs will appear as shown in Figure 43. Diamctrically opposite sidewal1s 335 on diametrically oppositc abutments 325 are not equally spaced from the reference alcis R. The misalignment of the arms (prior to slitting to form finger pairs) is indicated by the reference character Ma. The misalignment of resulting slit 30 i lincs 215 is indicated by the reference character Ms-1 and Ms-2.
The mismatches of finger thickness is indicated by the reference character M~. The mismatches of finger width is indicated by the reference character Mw.

, ~NO 93/05416 2 1 1 6 6 6 9 Pcr/US92/07389 As seen in Figure 43 when a fiber F is inserted into the channel 925 formed from arms or fingers with such misalignment(s), the fiber F will first strike a first, and then the second, of two diametrically opposcd ramping latcral surfaces 5 of the Icad-ins of thc abutmcnts 325 (Figurc 36~-before -contacting the sidewalls 335. Thcse inidal contact points on the fingcrs 225-2, 225-3 are illustrated in Figurc 44 at reference characters 3351. Those sidewalls 33S first contacted by the fiber F are forced apart in the directions 935A, 93SB. However, 10 since the bias forces generated by the movement of the ffrst contacted sidewalls are opposite, the-fiber F becomes centered in an interim centered position in a plane parallel to and centrally between such two surfaces. This interim centered position lies at some point in the plane indicated in Figure 44 15 by the line denoted at reference character P1.

Continucd advancement of the fiber F through the channel 925 causes the outer diameter of the fiber F to touch one or both of the rcmaining sidewall pair. The first touch of 20 the fiber to the sidewalls 335 is not the ~mal position of the fiber. The final position of the fiber is achievcd when the two fingers on the sidewall pair 225-1, 225-4 (Figure 44) have moved sufficiendy to center the fiber. These ~Inal contact points are illustrated in Figure 44 at reference characters 335F.
25 Since the bias forces created by movement of these last two sidewalls are also equal and oppositely directed the fiber is finally centered on the intersection of thc plane Pl and another plane PF~ The plane PF plane is parallel to and centrally located between the two surfaces touched at the contact points 335F.
30 ' The final position of the fiber F may be displaced from the desired reference axis due to the misalignments defined earlier and to other variations within manufacturing tolerances as described below. To make a positioning apparatus, or a 35 connector or an opto-electronic component utilizing the same, wo 93/05416 PCr/USg2/07389 for typical single mode optical fibers, the positioning apparatus must be able to handle fibers ranging in diameter from 125 to 128 micrometers. This range is found to be the typical diameter variation in quality single mode fibers.
,`~- -To insure that a fiber is hcld properly by all four fingers in the most preferred embodiment (Figures 3S to 45) the alignment of wafers for bonding during the fabrication process to be discussed must limit variadon of the misalignment in the 10 dircction across the grooves (the dimension Ma of Figure 43) to + or - 9.S micrometers. This direction of misalignment reduces the range of fiber diameter variation that arc handled in the most preferred embodiment. The misalignment of wafers in the other direction, along the length of the reference a~is 15 should be no more than twenty (20) micrometers. This direcdon of misalignment results in the clamping points of one pair of side-by-side fingers bdng axially displaced from those points of the other pair of sidc-by-side fingcrs, which would tend to bend the fiber slightly upwardly or downwardly.
The misalignment of the slit or saw cut, (Ms in l:igure 43) must be no more than ten (10) micrometers to avoid cutting into a sidewall Qf a groove whcn the slit width is sixty-six (66) mic~omctcrs wide, as obtained by using a typical si~ty (60) 25 micromcter saw.

The thic~ness of the flexure portion of the fingers should not ~ary by more than + or~- three (3) micrometers so spring forccs will be balanced with the fiber centered.
Commonly held tolerances in the microfabrication arts, such as in the microfabrication of devices as pressure rupture discs, are well within the above rangcs. ln fact, assuming the usc of an cnhanced posidoning apparatus ha~ing an alignment .

wo 93/05416 2 1 1 6 6 6 9 Pcr/uss2/073ss clamp, as shown in Figure 45, estimatcs show, in practice, the abovc maximum ~ariations would result in +/- 5 micrometers for sidewise misalignmont, M
+/- 1.5 micrometers for for flcxurc thic~Dess M~, +/- 10 micromctcrs for axial misalignme~of waf*s.
Othcr variations such as flexurc width &nd friction cncountered whcn a fiber is ccntcrcd by actions of thc four fingers are small. The net result using commonly achievablc manufacturing tolcranccs for microfabricatcd parts is wcll undcr onc (1) micromcter in displaccmcnt of thc ccnter point on the end face of thc fibcr from alignment with the refcrence axis. Even for thc maximum ~rariadons discussed abovc, the displaccmcnt of thc center of the fibcr cnd face from alignment with thc dcsired rcfcrcncc axis is wcll undcr onc (I) 1 5 micrometer.

- -o-O-o-With rcfcrcncc to Figurcs 42 and 44 (whethcr the fingers 20 arc mismatchcd or not) dnce the fibcr is suppor~d only at points of contact betwccn cach of the fingcrs in each ~ngcr pair, the length of thc fiber bohind the contacts is free to pivot.
To a~oid this evcntuality it is desirable to cnhance the ability of tbc positioning apparatus to precise position a fiber into 25 alignmcnt with a refcrence axis. To this end, it lies within the contemplation of the prcsent invention to pro~ide a clamp, generally indicated by the reference character 220, for engaging the ~Iber a predetermined distance 224 along the refercnce axis from the ~icinity of the points of contact 30 between the fiber F and the fingers 225. Such an enhanced positioning apparatus 205E is shown in Figure 45.

~; ~ As is best seen in Figuro 4~, the cnbanced positioning apparatus 205E compriscs- a ~ first,~ ~ forward, positioning apparatus 205 and a clamp 220 disposed a predetermined : :
~. ~

~V~ 93/0S416 PCr/US92/07389 distance 224 behind the positioning device 205. The clamp 220 is preferably implemented using a second positioning apparatus 205. However, any otber of the positioning apparatus 20, 201, 202, 203 or 204 disclosed herein may be 5 used as the clamp 220. Moreover, the clampin~ç~inction-may be performed by any arrangement of suitable form.

It is, of course, understood tbat an enhanced positioning apparatus similar to that shown by reference character 205E in 10 Figure 45 may be obtained using a forward and rearward arrangement of positioning apparatuses. Any combination of positioning apparatus 20, 20', 20", 203, 204, or 205 as disclosed herein may be used to implement the forward positioning apparatus and the clamp, thereby to form an enhanced 15 positioning apparatus 20sE.

The clamp 220 serves to position accurately a point on the center axis of the ~Iber into alignment with the reference axis. This second point on ~he center axis of the fiber is spaced 20 a predetermincd distance from the end face of the fiber. By pro~riding the clamp 220, any angular misalignment between the fiber axis and the reference axis is held to a minimum.

-o-O-o-It should also be apparent, similar to the situation disclosed in Figures 30 through 33, that a positioning device 205 or an enhanced positioning apparatus 205E in accordance with this invention can be used with an edge active or a 30 I surface active opto-electronic device to define an opto-electronic component.

In such a usage, the slab 745 would be extended, in the manner shown in Figures 30 and 31, to provide a pedestal 35 similar to the pedestal 174, on which an edge active device 170 wo 93/05416 2 1 1 6 6 6 9 PCr/US92/0738g may be mounted. The device 170 may be mounted to the pedestal in the manner earlier discussed. Altcrnatively, the slab may be modified to provide a pedestal similar to that shown in Figures 32 and 33, to accept a surfacc active device 5 170. As is the case in the earlier, the device ~ may~ take the form of a solid statc laser, a photodiode, or a light cmitting diode, whether these dcvices are edge or surface active. The axis X of the device is collinear with thc refcrence a~cis of the positioning apparatus 20S so that a fiber aligned by the 10 apparatus 205 with the reference axis will be in alignment with the device 170. The positioning apparatus 205 may be modified as suggested in Figure 31A, if desired, to accept a lens.

1 5 -o-0-o-If it is desired further, it should bc apprcciated that the posidoning apparatus 20S or an enhanced positioning apparatus 205E in accordance with this invention can be used to fashion a conncctor apparatus for holding the facial ends of two confronting fibers each in alignmcnt along a predetermined common reference axis.
:
To this cnd ~it~ is advantageous to mount onto the slab 745 a two confrontationally disposed positioning apparatuses 205 or two confrontationa!ly disposed enhanced positioning apparatuses 205E, (or a combination of the same).

The connector arrangement of positioning apparatuses ~; 30 205 or apparatuses 205E may be disposed in a suitably adapted housing generally similar to that shown in Figures 25 to 28, it being understood that the reference character 120 in Figures 25 to 29 indicates a connector formed of confronting apparatus 205 or apparatuses 205E. Most preferably, the housing should bc fabricated material with a low thermal coefficient of ~:

WO 93/05416 PCI`/US92/07389 211666~ 52 expansion over a temperature range from (~5 F to + 85 ~ F).
A suitable preferred material is a liquid crystal polymer such as that sold by Hoechst Celanese Corporation under the mark "Vectran. Conventional molding processes for that polymer can 5 be used to form the hollsing. ,~~

- o-O-o -The photolithographic microfabrication technique used to 10 manufacture a positioning appara~us in accordance with this invention may be understood from the following discussion taken in connection with Figures 46 to 52. Although the discussion is cast in terms of the manufacture of a fiber-to-fiber connector using the preferred embodiment of the 15 enhanced positioning apparatus 205E as shown in Figure 45, 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. ~For clarity of descriptive text, the basic 20 reference characters (i. e., without superscripts) of the elements of the positioning apparatus are used.) A silicon wafer 200 having an appropriate predete~nined crystallographic orientation is the- starting poin~ for fabrication 25 of the arms 22 of a positioning apparatus 20 in accordance with the present invention. It should be u~derstood tbat other single crystalline substrate n-aterials, such as germallium, may be u~ed provided appropriate alternative etchants and materials compatible with the selected al~rnative substrate 30 are used. The wafer 200 is polished on at least one surface.
Suitable silicon wafers are available from SEH Amelica, Inc., a subsidiary of Shin-Etsu Handotai Co. Ltd., Tokyo, lapan, loca~ed at Sparta, New Jersey. It should be understood that the wafer 200 can be of the "p-type", "n-type" or intrinsic silicon.

WO 93/OS416 2 1 1 6 6 6 9 PCl`/US92/07389 The substrate material is preferably (100) surface silicon because this material ean be etched by anisotropie etchants whicb readily act upon the (100) crystallographic plane but substantially do not etch the (111) plane. As a result the preferred truncated V-shaped grooves 36A, 36~he lroughs 60A, 60B, the lead-ins 68A, 68B and the eentral region 25A, 25B of the arms 22A, 22B between the abutments 32A, 32B
and tbe enlargements 54A, 54B are easily formed. The width and depth of such features are dependent upon the preselected width of the opening in the photolithographic mask being used and the time during which the etchants 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 1 S eross-seetion configurations are lequired, other predetermined erystallographic orientations of the silieon may be used. For example, if square eross-seetion features are desired, (110) surfaces silicon wafers ean be used. Other eross seetional eonfigurations for the features are, however, signifieantly more expensi~re and, as will be seen later, would require a more eomplieated eonfiguradon to obtain the fiber eentering aetion equivalent to that inherent in a V-groove.
.
Figure 46 is a plan ~riew of the wafer 200. The wafer 200 bas peripheral flats 201 and 202, as speeified by the SEMI
Standard. The flats 201, 202 primarily indieate orientadon of the erystallographie strueture of the silieon and are also used for wafer identi~leation and~mask alignment. The longer aat 201 indieates the direetion of erystallographie plane (110).
v 30 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 erystal.
;

WO g3/05416 ` PCr/USg2/07389 2I161i69 54 As will be developed, the peripheral regions 203 of the wafer 200, when prepared, carry alignment features, while the central region 204 of the wafer 200 has the structural features of the arm or foundation, as the case may be, of tbe positioning 5 apparatus formed thereon. , - ~ -Figure 47 shows a mask 210 with a patterns 212 of alignment features, such as orthogonal alignment grooves or alignmcnt through boles 212H and corresponding wells 212W, 10 thercon. The holes 212H are etched from the opposite surface of the wafer as are the wells.

If grooves are used, the grooves in each pattern 212 are graduated in size to accommodate various sized (diameter) 15 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 thc open top of the groovc) is 20 largcr than the diamctcr of thc fibcr so that thc ccnter of the fibcr is substantially coplanar with the surfacc of the wafer whcn the fiber is disposed in its associated groo~c.
Accordingly, for a 0.123 mm fiber, a groove 0.1506 mm is provided.~ Similarly, for a 0.124 mm ffber, the opcn top 25 dimcnsion of thc groove is 0.1518 mm. For a 0.125 mm fiber, thc open top dimension of the groove is 0.1531 mm; for a 0.126 mm ~ber the open top dimension of thc 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 48) containing to a predetermined number of structural features (i.c., amls or foundations mor slabs) of the positioning 35 apparatus 20 being formed. Since the typical wafer 200 is WO g3/05416 ~ I 1 6 ~ 6 ~ Pcr/usg2/o7~89 about 3.9381 inches (101.028 mm) in diameter and a typical connector 120 mcasures about three hundred fifty (350) micrometers at the widest location and is about two thousand eight hundred (2800) micrometers in length, tbe structural 5 features for approximately one thousand (lOO~l~onncctors 120 may be formed from thc ccntral region 204 of the wafer 200.

Pigure 48 is an cnlarged view of a ponion 220 of the 10 pattern provided on thc central region 214 of the mask 210.
In Figure 48, the pattern illustrated is that used to form a plurality of conjoined arms 22 used in a connector 120. The pattern 220 is formed on the surface of the central region 214 of the maslc 210 using a well-known step and repeat process to 1 5 cover the entire area.

T,he repetitive pattern 220 shown in Figure 48 is comprised of a plurality of columns 224 which are defined between an array of adjacent parallel scribe lines 226 and a 20 first and a second scparation linc 227A and 227B. Each column 224 contains tcn (10) discrete zones 228A through 228E that are symmetrical within the column 224 about a cutting line 230.
.
25 " ,, Secn betwecn two next adjaccnt scnbe lines 226 is the configuration of two arms 22 joined front cnd to front end.
Secn between three next adjacent scribe lines 226 is the configuration of two arms 22 joined lengthwise side to side.
Thc zone 228A corrcsponds to features defining the rcgion of " 30 the lead-in 68A of an ann 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 2~A of the arm 22A, while the zone 228D corresponds to features defining the region of the converging groove 36A on the arm 22A. The axis 50A of the converging groove 36A is offset from : :

WO 93/05416 . PCI/US92/07389 2116~9 56 the axis 70A of the trough 60A by the offset distance 100.
Finally, if provided, the zone 228E corresponds lo features deffning 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 5 on one side of the cutting line 230 is reversed,*om the position of the offset 100 on the opposite side of the cutting line, although this arrangement is not necessarily required.

The repedtive pattern for a mask of the arm 22B will be 10 similar to that shown in Figure 48 except that the direction of the offset distances 100 for the arm 22B will be the mirror image of the pattern for the arm 22A. As will become clearer berein, this mirror image relationship between the offsets is necessary so that so that features on the resulting arms 22A, 15 22B will register with each othcr 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 48 preferably 20 cor,rcspond 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 Icft unprotectcd. during subsequent etching steps. A negative resist;is cmployed but it should be apparent thal the location of 25 thc~hatched and clear arcas of Figure 48 may be reversed if desired. This w~uld alter somewhat subsequent steps, but in a manner lcnown to ~hose in the art.

Figures 49A through 49E illustrate the process steps 30 whereby a wafer 200 of crystalline silicon may be fonned into an array of arms 22A corresponding to the array shown on the mask of Figures 47 and 48. As seen în Figure 49A the wafer 200 is preliminarily covered with a layer 232 of a material that acts in a manner similar to a mask. Silicon dioxide (sio2) is 35 preferrcd, and is surfaced onto the polished operative surface WO 93/05416 2 1 1 6 S 6 9 PCl`/US92/07389 200S of the silicon wafer 200 by thermally growing the silicon oxide layer in an oxygen atmosphere at elevated temperature (circa eleven hundred fifty (1150) degrees Cdsius), as is Icnown. As indicated, silicon oxide is used because available 5 ctchants that attack silicon will also attaclc l~n,o~ photorësists but will attack the oxide only slightly. This sligbt attack is accounted for when dimensioning the photomaslc.

The layer of silicon oxide 232 is then covered with a 10 photoresist 234. Preferred is a positive resist, such as the mixture of 2-ethoxyethyl acetate, N-butyl acetate and xylene sold by Shipley Company, Incorporated of Newton, Massachusetts, as "Microposit Photoresist" 1400-37. The resist is spun onto the surface of the silica dioxide in accordance with 15 instrucdons set forth in the Shipley Microelectronic Products Brochute (1984) using standard apparatus such as that available from Headway Research Incorporated of Garland, Tcxas under model number ECR485.

The mask 210 is mounted atop thc wafer 200 and is aligned with respect to the flats 201, 202 of the wafcr 200 using alignment bars 23S. Thus, in a finished wafer the alignmcnt groovcs 212 are precisely positioned with respect to tbc flats on the wafer through the use of alignment bars 213 on the mask. The wafer 200 is cxposed to ultraviolet light through tbe mask 210 and subsequcntly de~eloped.

Since a positive resist~is used the unexposcd areas of the rcsist are washed away using de-ionized water, lea~ing the laycred arrangement of cxposed, hardened resist 234, silicon dioxide 232 and wafer 200, as shown in Figure 49B.

Next the pattern of the mask 210 is etched into the silica layer 232. Buffer hydrofluoric acid (HF) is preferrcd. This step results in the arrangement shown in Figure 37C. Those skilled WO g3/05416 PCI'/US92/07389 2116~69 58 in thc art will recognize that process variablcs such as, for example, concentration, time and temperature are all adjusted appropriately to opdmize results in all of the wet processing steps described.
,~-Thereafter, a sccond, differcntial, ctching step is performed to etch the silicon to form the featurcs of the arms 22A. The preferred anisotropic etchant is ten percent (10%) potassium hydroxide (KOH). Ethylene diaminc ("ED") pyrocatechol ("Pn) and watcr, in a mix of 750 ml ED, 120 gm P
and 240 ml water, may bc used. This etching produces the structural feature in the surface of the silicon illustratcd schemadcally in Figure 49D by refcrencc character 236. The depth of the feature 236 is controlled by controlling the etching time, as is wcll known. Of course, differential etching is sclf-li nidng for the inside angles of thc structure, if Icft to proceed.

Thc silicon dioxide layer 232is then remo~rcd by etching with buffcr hydroauoric acid (HF) and anothcr laycr of silica, i.c., silicon dioxidc, is grown on the surfacc. Ncxt, rcsist is depositcd on the surface of the wafer and is imagcd through a mask, as shown Figu~e 38. This results in a laycr 238 of . hardcned rcsist being formcd on thosc prcdetermincd portions of thc wafcr that arc to be bondcd (corrcsponding to zoncs 228C tbrough 228E and to troughs 60 (sec Figure 36)).

The silica layer is then etched from arcas that are to be bonded (See, Figure 49E) using hydrofluoric acid (HF). The resist layer 238 is s~ipped using ace~one, leaving a finished wafer ready for bonding.

This completes the fabrication of the first wafer 200 having the array of arms 22A thereon.

' ~vo g3/054l6 2 1 1 6 ~ 6 9 PCI`/US92/07389 As noted earlier, since the axis of the guideway 98A may be offset from the axis of the groove 92A, tbe mask for the arms 22B may not be identical with the mask used to form the 5 arms 22A. Accordingly, a second wafcr having,~r arrày of arms 22B thereon may be prcpared in accordance with the method stcps illustrated in Figure 49. The finished second wafcr (not specifically illustrated but hereinaftcr referred to by cbaracter 200') is similar in all respects cxcept in location of 10 the offset 100. f the wafers are the same, the second wafer is prepared exactly as the first.

A third wafer 200" is prepared using a foundation mask, a portion of which is shown in Figure 51. Pigure Sl is an 15 enlarged view of-a portion of the patlern 220' provided on the central region of thc foundadon mask (analagous to the pattern of tbe arm mask shown in Figure 36). The repetitive pattern 220' is comprised of a plurality of columns 244 which are defincd between an array of adjacent parallel scribe lines 246 20 and a ~ust and a second separation line 248A and 248B. Each column 244 contains four (4) discrete zones 250 that are symmetrical within tbe column 244 about a ccnter line 252.
Thc zones 250A define mounting surface 76 on a foundation 74. The zones 250B corrcspond to tbe surfaccs 82-provided on 25~ - the foundation. Thc wafa 200" containing the foundations 74 is exposed in a manner analogous to that shown in Figure 37, with the cxception tbat tbe exception that the solder mask c~posure is not carried out.~ However, the layer of silica is I removed from the surface of the wafer 200n.
Having prepared wafers for the arms 22A (the wafer 200), the arms 22B (the wafer 200') and the foundations 74 (the wafer 200"), the final assembly of the connector 120 may be made as is shown in Figure 40.

,,:

WO 93/05416 PCI`/US92/073~
2-~16~69 60 The wafer 200' is placed on top of the wafer 20.
Preferred methods of aligning wafers to be joined involve etching holes that go through one wafer and wclls (shallow holes) on the mating wafer accurately located by the precision 5 photomasks used for etching so that wafers are~aligned by matching tbrough bole with well at at Icast two locations on each wafcr. One method involves etching truncated pyramidal tbrough-boles and wdls so that when one wafcr is turned over and placed against the second wafer, each hole and well can be 10 matched by observation with a microscope as the wafers are positioned with precision adjustment mechanisms as are well known in the micromachining art. A better method is to etch V-groovcs forming crosses as holes and wells and matching by infrared source and camera searching for the brightest image 15 made by a beam passing through both wafers. Such in&ared equipmcnt is commercially available, (as, for example, &om Rcsearcb Deviccs Division of American Optical Corporation) a most preferred method is to etch a grid pattern of lines spacing from each other on the order of ten (10) micrometers 20 scparation. An infrared beam image can be inspected for the bright~st and most uniform lines in the image where etched lines are aligned letting the most infrarcd beam through the two silicon wafers. (This latter method is believed to be accurate to 0.5 micrometer, as compared to the~method with 25 crosses which is accurate to, typically, ten (10) micrometers .

As yet another alternative, the rcgistration of the featurcs on the wafer 200' to those on the wafer 200 is I effected using at least two and preferably four lengths of a 30 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 micromctcrs. Each of thc fibers is placed in groove in the groove ~rray 212 that most 35 closely corresponds to the measured diameter~ Each alignment ~VO 93/05~16 2 1 1 6 ~ 6 9 PCI/US92/07389 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 groovcs in the wafer 200' recdving the protruding portions of tbe alignment fibers thereby to precisely align the pattern of the two wafcrs. Since 10 the alignment groo-ves on each wafer are formed simultaneously with the formation of the features on the wafer, and since the mask for each wafer is formed optically 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 15 grooves 121 is shown, for clarity of illusmtion.

In a less preferred method, the assembly of superimposed wafcrs 200, 200' shown in Figurc 52 is bonded in a w~ct controlled atmosphere furnacc according to methods 20 dcscr bed in thc paper by Shimbo et al-9 "Silicon-to-silicon direct bonding method" puUished 10/86 in the lournal of Applied Physics, and in the paper by Lasky et aL, "Silicon on Insulator (SOI) By Bonding and Etchbaclc", IEDM 85. As seen in Figurc 52B the exterior surface 256' of thc waf* 200' is lapped 25 to reduce its thickness from it original thiclcness (typically approximately seventeen (17) mils) to a final thicl~ness of five (5) mils.

, The more preferred method of bonding uses the above 30 but avoids expensive lapping by etching parts of the arms and fingcrs as described below. and avoids forming an abutment on the slab.

The resuldng bonded structure is inverted and the 35 exterior surface 256' of the wafer 200' is mounted atop the WO 93/05416 PCI`/USg2/0738~1.

wafer 200". The alignment of these wafers is effected using a fixture employing quartz blocks 260 abutling against the flats 201, 202 of the wafer 200. The wafer 200' is tben bonded to the wafer 200n. It is to be understood that other bonding 5 techniques, such as those discussed in the paper by Wàllis 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 mctallic 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.
lS
The resultant three wafer bonded stack shown in Figure 52D may then be cut. Only the top two wafers 200, 200' of the bonded stack (containing the arms 22-lB, 22-2B and the arms 22-lA, 22-2A, respcctively, Figure 22) are first cut along the 20 lincs in the wafers corrcsponding to the cutting lines 230, 230' on tbe ann masks (~:igure 36). This cut is made using a blade that is on the order of 0.003 inches to create the distance 122 in Figu¢c 22. The bonded staclc is tbereafter cut, using a blade that is 0.01~ inches thick, along the lines in the wafers 25 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 200n, as wdl along the scribe lines 226, 226' and 246 (on the respecdve ; wafers 200, 200' and 200n) all of which are registered with 30 each other, thereby to yield from the bonded stack about one thousand of the fiber-to-fiber connectors 120.

- o - O - o -:~;

21 16~69 ~vo 93/05416 PCI/US92/07389 . 63 As noted earlier, thc positioning apparatus 205 shown in Figures 35 through 44 or an cnhanced positioning apparatus 205E shown in Figure 45 (and any connector or opto-electronic made using the same) is fabricated in a manner generally 5 similar to that previously discussed in the case~the`
positioning apparatus 20. Some spccific points may be noted.

A pordon of the top surface of a wafcr defines the surface 565B of a finger pair when fabrication is completed. An 10 adjoining portion of the wafer is ctched to form the surface 285 of cach finger pair.

On the opposite side of the wafer, a portion of that surface becomes surface 565A of cach abutment 545, while 15 another ponion of that wafer surface is etched to form surface 34S of the abutment 325 of cach clip 305. An adjoining portion of that surface of the wafer bctwccn thc surfaces 565A and 345 is etchcd slightly to form the major pordon of the surfacc 265 dcfining the flexurc. The abutments 54S, 32S are also ctched to 20 form sidcwall surfaces 625, 33S rcspccti~rdy. Each sidcwall surface 625i 335 defincs an anglc of S4.74 degrces from the planc of thc wafcr duc to the silicon crystal structurc.
.
- It is noted that the ctching process used does not makc 25 shaTp corncrs at thc ends of a groove. What would have becn a corner is etched inward on each side thereof. Due to the crystal structurc of the silicon two anglcd faccsare formcd at a corner location as shown in Figure~36B. The right anglc corners shown ! in thc Figure are formed by sawing or cutdng. The beveled 30 corners forrned are advantageous since they serve as guides to bring a cylindrical object, as the fiber, into the channels 905 and 925 formed by the troughs 605 and the grooves 365, respcctively.
-, ,; ' ~

-wo 93/05416 Pcr/usg2/073~8~

Several finger pairs are etched in a single silicon wafer.
All etching is done before the other fabrication steps.

A wafer containing containing a predetermined number 5 of unseparatcd of fingers is positioned on top of~inother wafer containing a corresponding predetermined number of unseparated of fingers. The wafers arc aligned so that the surfaces 565A (see Figures 36A) of the unseparated fingers on each wafer surface are touching in contact. The slight etching 10 of each wafer rclievcs the surfaces 345 on each unseparated fingcr to prevent their touching and being joincd.

The two wafcrs containing the unseparated fingers are placed.on a third wafer which contains a numbcr of 15 unseparated slabs 74S.

The wafers are joined, only~ at surfaces 565A, by hcating, to fusion tempcraturc in an oven. Known methods of joinder such as soldcring can also be uscd.
Aftcr thc joining stcps arc comp1eted thc silicon wafers are sliccd or cut, (i) down the centcrs of the groovcs 905, 925 (through the abutmcnts 305 and optionally, but prcfcrably through the abutments S45) to separate cooperating scts of 25 fingcrs, (ii) to separate sets of four fingcrs which will become positioning apparatus, and (iii), to cut thc bottom wafer. The bottom wafcr may be scparated to dcfinc a mounting slab for a set of four fingers to serve as a positioning apparatus (as in i Figure 35), to contain a both a forward and a rearward set of 30 four ffngers to define as a positioning apparatus with a rearward clamp (as in Figure 45), or to contain two confrontationaly disposed positioning apparatus, (each of which may include a single posidoning apparatus, or a positioning apparatus having the forward and rearward finger set.
: ~ ~

~vo 93/05416 2 1 1 6 6 6 9 PCr~US92/0738g ~ 65 - o-O -o -Those skilled in tbe art, having the benefits of the tcachings of the present invention as hereinabovc set forth, 5 may impart numerous modifications thcrcto. It~liould be understood that such modifications as hcrdn prescnted and any othcrs are to be construed as Iying within the contcmplation of the present invention, as dcfined by the appcnded claims.
WHAT IS CL~II~D IS:

Claims (45)

1. (Amended) An opto-electronic component comprising, in combination:
a foundation having a pedestal thereon;
a positioning apparatus mounted to the foundation, the positioning apparatus comprising at least a first and a second arm, the first arm being mounted to the foundation, each arm being movable from a first, closed, position to a second, entering, position, each arm having a first axial end and a second axial end thereon, 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, the first axial end of each of the arms being connectable to the foundation to remain a first predetermined radial distance from the reference axis while the arm occupies both the closed and the open positions, the second axial end of each arm being disposed the first predetermined radial distance from the reference axis while the arm occupies the closed position, the second axial end of each arm being displaceable radially outwardly to a second, greater, 66a radial distance from the reference axis while the arm occupies the centering position, 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, the second axial ends of each of the arms being responsive to further axial movement of the fiber through the channel by moving radially outwardly with respect to the reference axis against the bias force toward the centering position thereby to maintain the point on the fiber into alignment with the reference axis; 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 collinearly with the reference axis of the channel.

2. The opto-electronic component of claim 1, wherein the positioning apparatus further comprises:
a third arm movable from a first, closed, position to a second, centering, position, in the closed position the third arm cooperating with the first and the second arms to define the channel, the biasing means also biasing the third arm toward the first, closed, position such that the sum of forces on the three arms when in the centering position is substantially equal to zero, the third arm being arranged such that a cylindrical member introduced into the inlet end of the channel with the axis of the member spaced from the reference axis is initially displaceable by contact with at least one of the three arms to move the point on the center axis of the member into alignment with the reference axis regardless of the diameter of the cylindrical member, the third arm also being responsive to further axial movement of the member through the channel by moving against the bias force toward the centering position to position the point on the member into alignment with the reference axis.

3. An opto-electronic component comprising, in combination:
a foundation having a pedestal thereon;

a positioning apparatus itself comprising a first and a second arm, the first arm being mounted to the foundation, 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 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 a cylindrical member introduced into the inlet end of the channel with the axis of the member spaced from the reference axis is initially displaceable by contact with at least one of the arms to move a center point on an end face of the member toward alignment with the reference axis, the arms being responsive to further axial movement of the member through the channel by moving against the bias force toward the centering position to position the point on the face of the member into alignment with the reference axis by contact between the member 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 opto-electronic device aligning collinearly with the reference axis of 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 3 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 and second sidewalls in the first arm cooperate to define 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.

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 8 wherein each sidewall of the groove in the first arm and each sidewall of the groove in the second arm has an edge thereon, the edges of the sidewalls contacting the member.

10. The opto-electronic component of claim 7 wherein the second arm has a planar surface thereon and wherein each sidewall of the groove in the first arm has an edge thereon, the edges of the sidewalls contacting the member.

11. 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 member therebetween.

12. The opto-electronic component of claim 11 wherein the guideway has an axis therein, the axis of the guideway being offset from the axis of the channel by a predetermined distance.

13. The opto-electronic component of claim 3 wherein 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 force on each arm to bias each arm toward the closed position.

14. The opto-electronic component of claim 3 wherein the foundation and the first and the second arms are each fabricated from a crystalline material.

15. The opto-electronic component of claim 3 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 groove so defined in each arm has a truncated V-shape.

16. The opto-electronic component of claim 6 wherein the foundation and the first and the second arms are each fabricated from a crystalline material.

17. The opto-electronic component of claim 6 wherein 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 force on each arm to bias each arm toward the closed position.

18. The opto-electronic component of claim 17 wherein the foundation and the first and the second arms are each fabricated from a crystalline material.

19. The opto-electronic component of claim 6 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.

20. The opto-electronic component of claim 6 wherein each arm has a trough disposed therein, each trough being disposed on an arm a predetermined distance behind the groove in that arm, in the closed position the troughs in the arms cooperating to define a guideway for guiding the member toward the channel.

21. The opto-electronic component of claim 20 wherein the guideway has an axis therein, the axis of the guideway being offset from the axis of the channel by a predetermined distance.

22. The opto-electronic component of claim 3 wherein the opto-electronic device is an edge active device.

23. The opto-electronic component of claim 3 wherein the opto-electronic device is a surface active device.

24. The opto-electronic component of claim 3 wherein the opto-electronic device is a solid state laser.

25. The opto-electronic component of claim 3 wherein the opto-electronic device is a solid state light responsive diode.

26. An opto-electronic component comprising, in combination:

a foundation having a pedestal thereon;

a positioning apparatus itself comprising a first and a second arm, the first arm being mounted to the foundation, 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 first fully funnel-like channel having a reference axis therethrough, the first funnel-like channel having an inlet end and an outlet end, the arms being arranged such that a cylindrical member introduced into the inlet end of the first funnel-like channel with its axis spaced from the reference axis is displacable by at least one of the sidewalls to move a center 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 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 cylindrical member 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 collinearly with the reference axis of the channel.

27. The opto-electronic component of claim 26 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.

28. The opto-electronic component of claim 26 wherein the first and second arms are each fabricated from a crystalline material.

29. An opto-electronic component comprising, in combination:
a foundation having a pedestal thereon, a postioning apparatus mounted to the foundation, the positioning apparatus comprising:
a set of four fingers, each of the fingers having a sidewall thereon, each finger being articulably movable from a first, closed, position to a second, centering, position, in the closed position the sidewalls of the fingers 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 fingers toward the first, closed position with a predetermined biasing force such that the sum of the biasing forces on the fingers when the fingers are in the centering position is substantially equal zero, each of the fingers being arranged such that a cylindrical member introduced into the inlet end of the channel with the axis of the member spaced from the reference axis is initially displaceable by contact with the sidewall on at least one of the fingers to move a center point on an end face of the member toward alignment with the reference axis, each of the fingers being responsive to further axial movement of the member through the channel by deflecting against its biasing force to position the center point on the end face of the member into alignment with the reference axis by contact between the member and a point of contact on each of the fingers; 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 collinearly with the reference axis of the channel.

30. The opto-electronic component of claim 29 wherein each of the fingers is axially elongated and has a first and a second axial end thereon, and wherein the sidewall is disposed at the first axial end, each finger having a reduced thickness region disposed thereon intermediate the first and the second axial ends, the reduced thickness portion defining a flexure in each finger which, when each finger is deflected by contact with the member, generates a restoring force on each finger to bias each arm toward the closed position.

31. The opto-electronic component of claim 29 wherein each of the fingers is fabricated from a crystalline material.

32. The opto-electronic component of claim 29 wherein the fingers are arranged into a first and a second pair of fingers.

33. The opto-electronic component of claim 29 wherein the opto-electronic device is an edge active device.

34. The opto-electronic component of claim 29 wherein the opto-electronic device is a surface active device.

35. The opto-electronic component of claim 29 wherein the opto-electronic device is a solid state laser.

36. The opto-electronic component of claim 29 wherein the opto-electronic device is a solid state light responsive diode.

37. The opto-electronic component of claim 29 further comprising:

an alignment clamp for engaging the member at a predetermined distance along the reference axis from the vicinity of all of the contact points on the sidewalls of the fingers, the clamp engaging the member so as to position accurately a predetermined second point on the center axis of the member into alignment with the reference axis.

38. The opto-electronic component of claim 37 wherein the alignment clamp comprises:

a second positioning apparatus itself comprising:
a second set of four fingers, each of the fingers in the second set having a sidewall thereon, each fingers in the second set being articulably movable from a first, closed, position to a second, centering, position, in the closed position the sidewalls of the fingers in the second set cooperating to define a second channel having a second reference axis therethrough, the second channel having an inlet end and an outlet end, the second reference axis being collinear with the first reference axis, means for biasing each of the fingers in the second set toward the first, closed position with a predetermined biasing force such that the sum of the biasing forces on the fingers in the second set when the same are in the centering position is substantially equal zero, each of the fingers in the second set being arranged such that a cylindrical member introduced into the inlet end of the second channel with the axis of the member spaced from the second reference axis is initially displaceable by contact with the sidewall on at least one of the fingers in the second set to move the center point on the end face of the member toward alignment with the second reference axis, each of the fingers in the second set being responsive to further axial movement of the member through the channel by deflecting against its biasing force to move the second point on the center axis of the member toward alignment with the second reference axis, each of the fingers in the second set also deflecting against its biasing force to position accurately the predetermined second point of the member into alignment with the reference axis by contact between the member and a point of contact on each of the fingers in the second set.

39. The opto-electronic component of claim 38 wherein each of the fingers in the second set is axially elongated and has a first and a second axial end thereon, and wherein the sidewall is disposed at the first axial end, each finger in the second set having a reduced thickness region disposed thereon intermediate the first and the second axial ends, the reduced thickness portion defining a flexure in each finger in the second set which, when each finger in the second set is deflected by contact with the member, generates a restoring force on each finger in the second set to bias each such finger toward the closed position.

40. The opto-electronic component of claim 38 wherein each of the fingers in the second set is fabricated from a crystalline material.

41. The opto-electronic component of claim 38 wherein the fingers in the second set are arranged into a first and a second pair of fingers.

42. The opto-electronic component of claim 38 wherein the opto-electronic device is an edge active device.

43. The opto-electronic component of claim 38 wherein the opto-electroninc device is a surface active device.

44. The opto-electronic component of claim 38 wherein the opto-electronic device is a solid state laser.

45. The opto-electronic component of claim 38 wherein the opto-electronic device is a solid state light responsive diode.