Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4202—Packages, e.g. shape, construction, internal or external details for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
  • G02B6/422—Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements
  • G02B6/4225—Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements by a direct measurement of the degree of coupling, e.g. the amount of light power coupled to the fibre or the opto-electronic element
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4292—Coupling light guides with opto-electronic elements the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements

Definitions

• This invention relates to an optical connector and, in particular, to an optical connector which is adapted to receive a terminated fibre and to locate said fibre for optical interaction with an optical device contained in the connector.
• a complete optical connector can be regarded as comprising two major items, namely a plug and a socket. Connection clearly involves bringing together the two separate items so as to establish optical communication between them.
• the plug comprises a waveguiding structure, especially an optical fibre which has been suitably terminated.
• the termination usually comprises a ferrule, eg a brass ferrule, which is mounted on the end of the optical fibre.
• the termination also includes a cap which is spring loaded to the ferrule. The cap and spring serve to hold the ferrule in place after its insertion into the socket.
• This invention relates to the socket part of the connector and this part usually includes an optical device which maybe an active device or a passive device ⁇
• Active devices include signal generators, eg a semiconductor device which converts electric power into an optical signal. Examples of such semiconductor devices include light emitting diodes (LEDs), edge light emitting diodes (ELEDs), and a wide variety of semiconductor lasers.
• a signal generator often provides a divergent beam which is inconvenient for forming optical connections. In such circumstances it is usual for the source component to include lenses which either collimate the beam or cause it to converge to a focus.
• the active device may be an optical detector, eg a semiconductor device which converts an optical signal into an electrical signal. Examples of such devices include photodiodes and PIN diodes.
• the optical component may be a passive device such as a waveguiding structure, eg a fibre which is permanently located in the connector.
• a connector The purpose of a connector is to provide optical inter-connection between a (terminated) fibre temporarily inserted into the socket of the connector and another optical device which is permanently comprised in the connector.
• optical inter-connection it is important that the two optical components are accurately located so that a beam provided by one is captured by the other. For example, it may be important that a beam from a signal generator is accurately focused onto the end of a fibre temporarily located within the connector.
• accurate relative position is an important requirement for an optical connector.
• One of the reasons for using a connector rather than a permanent connection is the necessity to make, break and remake the connection. It is important that the accurate location be achieved every time a new connection is made.
• This invention is based upon the recognition of certain features of optical inter- connection and it takes advantage of these features to provide an effective connector of simple structure. More specifically, the invention is based upon the recognition of two features and their interaction. The two features are
• Reproducibility means that a particular socket will accurately and repeatedly return an inserted ferrule to the same position, that is to its own arbitrarily selected position rather than a predetermined position.
• the accurate machining mentioned above is necessary if it is intended to place a ferrule at a predetermined point.
• simpler structures with much looser tolerances are effective if it is only necessary for accurate repeatability for location at the same arbitrary location.
• an optical connector comprises an optical device, eg active and passive devices as described above, directly or indirectly mounted on the first side of a flange and a sleeve extending from the second side of the flange said sleeve being adapted to receive and reproducibly locate a fibre ferrule containing the end of an optical fibre, said location being suitable for optical interaction between the fibre and the optical device via an aperture in the flange, wherein said sleeve has a larger cross sectional area in an innermost zone adjacent to said second side of said flange than in a deformable zone further from said flange whereby the insertion of a fibre ferrule to abut the flange for reproducible longitudinal location expands the sleeve in its deformable zone whereby the deformable zone grips the ferrule for reproducible location within
• the deformable zone is divided into a plurality of spring segments by a plurality of longitudinally extending slits.
• the number of slits is equal to the number of segments and that the segments are organised in diametrically opposed pairs so that the number is even, eg 2, 4, or 6.
• the innermost zone takes the form of an undivided collar having a diameter greater than that of the tip of the ferrule to be inserted and the deformable zone takes the form of a plurality of spring members, eg spring members arranged as described above, extending from said collar.
• the sleeve may be located inside a tubular protective member which is also connected to the flange.
• the tubular protective member may include attachment means for holding the cap of a fibre termination whereby the spring loading between the cap and the ferrule urges the ferrule into abutment with the flange for more precise location.
• the first side of the flange is connected directly or indirectly to an optical member and this assembly will be well known to persons skilled in the art.
• the protective tubular member may provide attachment to an operational panel.
• the invention includes the assembly of the optical connector and this is preferably achieved by the active technique described above.
• a particularly convenient form of attachment for the optical device to the flange and the active technique for assembly are both described in our co-pending UK patent application number 9217732.8.
• FIG. 1 is a pair of perspective drawings which show the general appearance of the key component of the connector
• Figure 2 is an end view of the component shown in Figure 1 ,
• Figure 3 is a longitudinal cross section of the component shown in Figures 1 and 2; and Figure 4 is a longitudinal cross section showing the component of Figures 1-3 mounted into a complete connector having a fibre termination located therein.
• the key component has a flange 10 which has a first face 11 which, in the completed device as shown in Figure 4, supports an optical component.
• the flange 10 has a second face 12 from which a sleeve 14 extends.
• the sleeve 14 has a collar 15 and a deformable zone formed of two spring members 16a and 16b which are separated from one another by longitudinally extending slits 17a and 17b.
• the flange 10 has a central aperture 13 for the passage of optical signals.
• the diameter of the deformable zone is defined by the distance between the spring segments 16a and 16b and this diameter is smaller than the diameter in the collar 15.
• Ferrules are usually between 2.7 mm and 2.6 mm in diameter so a ferrule will force apart spring segments 16a and 16b but it is small enough to be contained within the collar 15.
• an inserted ferrule is gripped, and located, by the spring members 16a and 16b and the end face of the ferrule can be placed in abutment with the second face 12 of the flange 10 whereby the inserted ferrule is placed in a reproducible location.
• the component illustrated in Figures 1 , 2 and 3 is machined from a resilient material such as phosphor-bronze. This is a convenient operation for the mass production of items at a reasonably low price. Since the items are intended for mass production it is important to compare one with another. Each item will have its own individual point for locating an inserted ferrule but this will vary substantially from item to item. In other words, it is not necessary to define a predetermined locational point and to ensure that each item brings a ferrule to this predetermined point. To this extent each item is its own individual. Nevertheless each single item is reproducible in that it will accurately replace an inserted ferrule to its own individual point. Therefore, as will be explained below, mounting an optical device in relationship to this individual point will enable accurate relocation of the ferrule for optical interaction every time.
• a resilient material such as phosphor-bronze
• FIG 4 A fully assembled connector in accordance with the invention is shown in Figure 4.
• This Figure includes a fibre ferrule which is temporarily inserted for optical communication.
• Figure 4 which is a longitudinal cross section, the component of Figures 1, 2 and 3 is generally indicated by the numeral 40. Since this component has been fully described it is not necessary to repeat this description.
• the left hand portion of Figure 4 illustrates the optical package 42 which is attached to the first face of the flange 10.
• the right hand portion illustrates the socket arrangements.
• FIG. 4 shows the connector with a fibre ferrule 60 located in the sleeve.
• the ferrule contains a fibre 61 and the ferrule 60 is part of the termination of this fibre which extends to whatever location is appropriate.
• the termination also includes a cap 62 which is spring loaded to the ferrule 60 by spring 63.
• the cap 62 includes a retaining lip 64 which is located in a retaining groove 43 of the tubular protective member 41.
• the optical package 42 which is located on the left hand side of the flange 10, comprises an active component, eg an LED 50 which is positioned to provide optical signals to the fibre 61 via the aperture 13. These signals are acquired by the fibre 61 for onward transmission.
• the LED 50 is contained inside encapsulation 51 (which is the conventional way of mounting an active optical device).
• the encapsulation 51 is located inside an intermediary component 52 one face of which is in contact with the first face 11 of the flange 10. It will be appreciated that this arrangement makes it possible, during the assembly of the connector, to move LED 50 to its optimum position for interaction with the fibre 51.
• the intermediary component 52 provides freedom of movement in cross sectional directions so that the LED 50 can be moved onto, for example, the optical axis of the fibre 61.
• the encapsulation 51 can be slid in or out of the intermediary component 52 so that the distance between LED 50 and the end of the fibre can also be optimised.
• glue is applied to the various surfaces so that the optimum location is made permanent.
• the optical package 42 is enclosed in a protective cover 45 which also engages with the flange 10 and the panel 44.
• the connector is assembled as follows.
• Ferrule 60 is located in the sleeve 14 which is clamped.
• the fibre 61 is connected to an optical detector for measuring the strength of signals acquired by the fibre.
• the component 40 including the inserted ferrule is clamped during the assembly process.
• the encapsulation 51 is placed inside the intermediary component 52 and this is moved into approximately the correct position with the component 52 in contact with the flange 10. At this stage electric power is supplied by the leads 53 so that LED 50 produces its optical signal which is acquired by the fibre 61.
• the encapsulation 51 is moved until maximum transmission is obtained. This is possible because the intermediary component 52 permits free movement of the encapsulation 51 in three dimensions (at least over the required distances).

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Mechanical Coupling Of Light Guides (AREA)
• Optical Couplings Of Light Guides (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=10730577

Family Applications (1)

Country Status (5)

Families Citing this family (8)

Family Cites Families (4)

• 1993
  • 1993-02-17 GB GB939303169A patent/GB9303169D0/en active Pending
• 1994
  • 1994-02-16 WO PCT/GB1994/000313 patent/WO1994019718A1/en not_active Application Discontinuation
  • 1994-02-16 AU AU60087/94A patent/AU6008794A/en not_active Abandoned
  • 1994-02-16 JP JP6518739A patent/JPH08500195A/ja active Pending
  • 1994-02-16 EP EP94906337A patent/EP0636253A1/en not_active Withdrawn

Non-Patent Citations (1)

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