FIBER OPTIC CONNECTOR AND CONNECTOR ASSEMBLY

Abstract: The connector (10) comprises a cartridge (12) containing an active optical device (36), for example and a light emitting diode, in a can (42) fitted into a metal tube (14) in which is fixed a fiber optic needle (8') in light transmitting relationship with the active optical device (36). A second metal part (30) is secured to the tube (14) by way of an insulator (24), and is connected to an electrode (44) of the active optical device (36). The connector (10) can be plugged into a support member (58) of the connector assembly or that the active optical element (36) is connected to current via terminals (86) and (92) in the support member (58), and so that the optical needle (8') enters a ferrule (57), so as to be in light transmitting relationship with a further optical needle (8'') in the ferrule (57).

Description: FIBER OPTIC CONNECTOR AND CONNECTOR ASSEMBLY This invention relates to a fiber optic connector and to a fiber optic connector assembly, incorporating an active optical device, which may be either a light sensitive device, for example, a light sensitive diode, or a light emitting device, for example, a light emitting diode or a laser. There is described in EP-A1-96511 , a fiber optic connector comprising an optical needle in the form of a length of optical fiber having a rigid concentric coating of constant thickness , and which is formed at each of its opposite end faces with an optical surface; an active optical device; and means for supporting the optical needle and the optical device, for the transmission of light therebetween. The present invention is intended to provide such a connector, which is compatible with a fiber optic connector assembly which can readily be assembled and disassembled by virtue of the plugability of the parts of the assembly. According to one aspect of the invention, a fiber optic connectcjr, as defined in the second paragraph of this specification, is characterized in that the supporting means comprises a cartridge in which said optical needle is fixed with a free end portion thereof projecting from the cartridge, and which contains said active optical device, the cartridge having external electrodes which are electrically insulated from one another and are connected to corresponding electrodes of the optical device, for the application of electrical potential thereto. The connector can be supplied to the user, for incorporation in a fiber optic connector assembly having electrical terminals for connection to said external electrodes and means for supporting the cartridge, with the end face of said projecting free end portion in light transmitting, or light receiving, relationship with a further optical fiber, for example with a further optical needle. Since an optical needle is necessarily rigid and can thus act as a plug, two optical needles can be connected in light transmitting relationship by inserting their end portions through opposite ends of a rigid alignment member which may be in the form of a tubular ferrule. The needle end portions and the ferrule can be dimensioned to very close tolerances , especially where the ferrule is of ceramic material, so that said end portions are slidably and snuggly received in the ferrule, whereby the needle end portions are firmly relatively positioned and whereby the light transmitting connection can readily be made and broken. Although there is described in US-A-4,186,996, a modular fiber optic connector incorporating an active optical device, the connector does not comprise an optical needle and the fiber is positioned in relation to the active optical device, by means of a resinous potting material. According to US-A— ,273,413, a fiber optic connector incorporating an active optical device comprises a resilient ferrule containing a photoelectric element. The connector does not, however, comprise an optical needle. Although US-A-3,840,889 and US-A-4,461,538 concern , connectors ' _- in which an optical fiber is retained in light transmitting relationship with an active optical device, neither of these connectors is in the form of a -cartridge and neither comprises an optical needle. The coating of the optical needle may be provided by electroplating the fiber with metal and then etchin the coating so provided to the required thickness, after producing said optical surfaces. The cartridge may be in the form of a tube comprising a first metal part having a closed end formed with a bore in which the needle is fixed, for example by cold soldering or welding, the first metal part being connected to a second metal part through the medium of an insulator. The first metal part contains the active optical device, with, a light transmitting, or a light receiving element, for example a lens, of the active device proximate to the adjacent end face of the optical needle. The active optical device can be press fitted into the first metal part to make electrical contact between a metal can of the active device and the first metal part, another electrode of the active device being electrically connected to the second metal part so that said metal parts constitute the respective external electrodes of the cartridge. The active optical device may be, for example, a light emitting diode, the can of which is the collector electrode of the active optical device, an emitter electrode insulated from the can, being connected to said second metal part. The metal parts of the cartridge may be made, for example, of brass. According to another aspect of the invention, a fiber optic connector assembly comprising a first optical needle in the form of a length of optical fiber having a rigid coating of constant thickness, and which is formed at each of its opposite end faces with an optical surface; an active optical device; and means supporting said optical needle and said active optical device for the transmission of light therebetween; is characterized by a second optical needle also in the form of a length of optical fiber having a rigid coating and which is formed at each of its opposite end faces with an optical surface; a rigid alignment member, slidably and snuggly receiving one end portion of each optical needle; and means retaining said needle end portions in the alignment member, with their optical end faces in proximate face to face relationship, said -retaining means being provided with electrical terminals, electrically connected to corresponding electrodes of the optical device, for the application of electrical potential thereto. The first optical needle may be that of a fiber optic connector according to said first aspect of this invention and the second optical needle, which may be connected to a light transmitting or a light receiving circuit, may have, spaced back from said alignment member, an enlarged cross -section portion received in a bore in a first support member having latch arms for retaining the alignment member in position. The connector may be arranged in a second support member having a hood, receiving the latch arms of the first optical connector and thereby retaining them in a latching position, and may be releasably secured in a bore in the second support member, by means of the terminals, which may have contact portions engaging in the depressions in the electrodes of the cartridge with a snap action. For a better understanding of the invention and to show how it may be carried into teffect, reference will now be made by way of example to the accompanying drawings in which: Figure 1 is a sectional view of a fiber optic connector assembly comprising a fiber optic connector; Figure 2 is an isometric view of an optical needle; Figure 3 is a sectional view of the fiber optic connector; and Figure 4 is an exploded, elevational view of the fiber optic connector. One form of optical needle 2 will now be described with reference to Figure 2. The needle 2 consists of a short length of optical fiber 4 having a rigid concentric metal coating applied to the fiber by electroplating and having been etched away to an extent to produce a needle-like free end portion 8 of metal coated fiber, joined -by a tapered transition portiori 9 to an enlarged portion- 6 over which the metal coating is of its original thickness . Each opposite end face of the fiber was formed with an optical surface prior to the coating having been etched. The coating may be etched to an extent to produce an optical needle of constant cross-sectional area or to produce a transition portion of any required taper. A fiber optic connector 10, shown in Figures 1, 3 and 4, comprises a circular cross-section cartridge 12 having a tubular first metal part 14 having a closed end 16 formed with a concentric bore 18 communicating with circular cross -section, internal cavity 20 and opening into a forward face 22 of the part 14. The rear end of the part 14, which is open, is formed with a skirt 23 receiving a forward part of an insulator 24 having a central opening 26. Said forward part is bounded by a radial flange 28 abutting the rear end of the skirt 23. A second metal part 30 of the cartridge 12 has a forwardly projecting skirt 32 receiving a rear part of the insulator 24 on the opposite side of the flange 28 to said forward part, with the forward end of the skirt 32 abutting the flange 28. The part 30 has a central, circular cross-section through bore 34 concentric with the opening 26, the bore 34 defining a rearwardly flared, frusto-conical solder cup 35. The parts 14 and 30 have arcuately concave peripheral grooves 48 and 50, respectively. The parts 14 and 30 and the insulator 24 are secured in their assembled position by means of an adhesive. An active optical device 36, in the form of a light emitting diode in a metal can 42 having a lens 38 at its forward end and a radial flange 40 at its rear end, was press fitted into the cavity 20 of the part 14, prior to the assembly of the metal parts 14 and 30 to the insulator 24. As shown in Figure 3 , the flange 40 is lodged in the skirt 23 and is engaged by the insulator 24. The can 42 constitutes the collector electrode of the diode 36, an emitter electrode 44 thereof projecting rearwardly from the can 42 and being insulated therefrom. As shown in Figure 3, the electrode 44 extends through the opening 26 in the insulator 24 and into the cup 35 of the bore 34 and is soldered therein at 46 * The parts 14 and 30. of the cartridge 14 may be made, for example, , of brass . There is secured in the bore 18 of the metal part 14, a fiber optic needle 8 ! of constant cross -sectional area, similar to the portion 8 of the needle 2 shown in Figure 2, and having optical surfaces 42 and 54, respectively, at its ends. The needle 8' is secured in the bore 18 , with " its optical face 52 in light receiving relationship with the lens 38 , for example, by cold soldering or welding. The fiber optic connector assembly shown in Figure 1 comprises a first support member 56 supporting a fiber optic needle 2' and a rigid alignment member in the form of a tubular, circular cross-section ferrule 57, and a second support member 58 supporting the fiber optic connector 10. The support member 56 has a body 60 formed with a circular cross-section bore 62 receiving a larger cross-section portion 6' of the needle 2', a smaller, constant, cross-section portion 8' of which is snuggly and slidably received in a central bore 64 of the ferrule 57 which may be made, for example, of glass , ceramic, or metal. The bore 64 has a flared, needle end guiding mouth 65 at each end thereof. The ferrule 57 is enclosed in a longitudinally divided, circular cross -section, hood 66 projecting from the body 60 and providing resilient latch arms 68 enclosing the ferrule 57. The support member 58 has a body 70 having a circular cross-section hood 72 receiving the hood 66 of the support member 56, the body 70 being formed with a circular cross-section bore 74 receiving the connector 10 and communicating with a second and smaller circular cross-section bore 76 opening into a forward face 78 within the hood 72, of the body 70. The needle 8' of the connector 10, which, extends through the bore 76, is snuggly and slidably received in the bore 64 of the ferrule 57, with its optical face 54 in light transmitting, face to face, relationship with the optical face 78 of the portion 8' of the needle 2' . Spaced, opposed, longitudinal grooves 80 and 82, the groove 80 being longer than the groove 82, are formed in the wall of the bore 74. The groove 80 has force fitted thereinto an electrical terminal 86 having a cantilever spring portion 88 with a bowed contact portion 90 engaged in the groove -48 of the connector 10. A further electrical terminal 92, force fitted into the groove 82 has a cantilever contact portion 94 having a bowed contact portion 96 engaged in the groove 50 of the connector 10. The terminals 86 and 92 have contact tails 98 and 100, respectively, which are soldered to printed supply conductors PC. and PC„, respectively, on a printed circuit board PCB , for the application of electrical potential to the active optical device 36 via the metal parts 14 and 30 of the cartridge 12. With the parts of the assembly shown in Figure 1 in a disassembled condition, the latch arms 68 are opened, the ferrule 57 is inserted therebetween and the hoods 66 and 72 are mated, the connector 10 and the needle 2' being then plugged into the bores 62 and 74, respectively, so that the needle 8' and the portion 8' of the needle 2' slide snuggly into the bore 64 of the ferrule 57 to position the optical faces 54 and 78 in proximate, face to face relationship. The connector 10 fits into the bore 74 with a snap action, as the bowed contact portions 90 and 96 of the terminals 86 and 92 engage in the respective grooves 48 and 50 of the cartridge 12. The optical face (not shown) of the needle 2' , opposite to its optical face 78, is connected to an optical circuit by means of an optical connector which may comprise, for example, a ferrule similar to the ferrule 57, for receiving an optical needle through either end.

Claims: CLAIMS 1. A fiber optic connector 10, comprising an optical needle 8 r in the form of a length of optical fiber having a rigid concentric coating of constant thickness, and which is formed at each of its opposite end faces with an optical surface 52 and 54; an active optical device 36; and means 12 for supporting the optical needle 8' and the optical device 36, for the transmission of light therebetween; characterized in that the supporting means comprises a cartridge 12 in which said optical needle 8' is fixed, with a free end portion thereof projecting from the cartridge 12, said cartridge 12 containing said active optical device 36, and having external electrodes 14 and 30 which are electrically insulated from one another and are connected to corresponding electrodes of the optical device 36 for the application of electrical potential thereto. 2. A connector according to claim 1, characterized in that the cartridge comprises a first metal part having a cavity 20 receiving the active optical device 36, a bore 18 formed in a wall of said first metal part 14 communicating with the cavity 20 and receiving an end portion of the optical fiber 8' , which is fixedly secured in the bore 18. 3. A connector according to claim 2, characterized in that an electrode of the active optical device 36 is constituted by a can 42 which is press fitted into the bore 20, another electrode 44 of the active optical device 36 extending through a bore 26 in an insulator 24 intermediate the first metal part 14 and a second metal part 30 of the cartridge 12, the second electrode 44 of the active optical device being electrically connected to the second metal part 30 of the cartridge 12. 4. A connector according to claim 3, characterized in that each of said metal parts 14 and 30 is of circular cross section and is formed with a peripheral groove 48 or 50 for receiving a contact portion 90 or 96 of an electrical terminal 86 or 92 with a snap action. 5. A fiber optic connector assembly comprising, a first optical needle 8' in the form of a length of optical fiber 4 having a rigid coating and which is formed at each of its opposite end faces 52 and 54 with an optical surface; an active optical device 36 ; and means supporting said optical needle 8' and said active optic device 36 for the transmission of light therebetween; characterized by a second optical needle 8" also in the form of a length of optical fiber 4 having a rigid coating and which is formed at each of its opposite end faces with an optical surface 78; a rigid alignment member slidably and snuggly receiving an end portion of each optical needle 8' and 8" ; and means 56 and 58 for retaining said end portions in the alignment member 57 with their optical surfaces 54 and 78 in proximate face to face relationship, said retaining means 58 being provided with electrical terminals 86 and 92, electrically connected to corresponding electrodes 42 and 44 of the optical device 36 for the application of electrical potential thereto. 6. An assembly according to claim 5 , characterized in that said retaining means comprise a first support member 56 and a second support member 58, the first support member 56 having a first -hood 68 containing the alignment member 57 and being received in a second hood 72 projecting from the second support member 58. 7. An assembly according to claim 6, characterized in that the first hood 68 is divided longitudinally of the alignment member 57 to provide latch arms 68 for releasably containing the alignment member 57. 8. An assembly according to claim 6 or 7, characterized in that the active optical device 36 is contained in a cartridge 12 received in a bore 74 in the second support member 58, said end portion of the first optical needle 8' projecting from the cartridge and the second optical needle 8" being supported by the first support member 56 with said end portion of the second optical needle 8" projecting therefrom into the alignment member 57. 9. An assembly according to claim 8 , characterized in that the cartridge 12 has external electrodes 14 and 30 electrically connected to corresponding electrodes 42 and 44 of the active optical device 36 , electrical terminals 86 and 92 projecting into the bore 74 of the second support member 58, being engagable with said external electrodes 14 and 30 with a snap action. 10. An assembly according to claim 5, characterized in that the active optical device 36 is incorporated in a fiber optic connector according to claim 1. 11. An assembly according to any one of claims 5 to 10, characterized in that said alignment member is in the form of a tubular ferrule 57. 12 ^ A fiber optic connector substantially as hereinbefore described with reference to the accompanying drawings. 13. A fiber optic connector assembly substantially as hereinbefore described with reference to the accompanying drawing.

Inventors: TEN BERGE EDUARDUS FRANCISCUS, VAN ALST GERARDUS MARIA, TEN BERGE, EDUARDUS, FRANCISCUS, ANTONIUS, VAN ALST, GERARDUS, MARIA
Applicants: AMP INC, AMP INCORPORATED
Application year: 1988
Main classification: G02B6
IPC codes: G02B6