Abstract: A structure for providing an N by N optical switch includes input and output structures disposed on either side of a planar electronic shutter array. Each of the input and output structures, which respectively provide optical signal splitting and combining, is realized by the stacking of N molded optical elements. Each element is formed of a plurality of molded materials with one providing an optical waveguide and the other providing a supporting structure for such waveguides. Advantageously, both the input and output structures utilize the same molded optical element and are fabricated in an identical manner. After such fabrication, the one structure to be designated as the output structure is rotated 90 degrees with respect to the input structure prior to abutment against the planar electronic shutter array.

Abstract: A molded polymeric resin-filled coupler comprising two low-refractive index plastic molded subassemblies. One subassembly has an optically finished mixing region, with a channel that has a V shaped lower portion. The mixing region subassembly is covered with a lid subassembly of the same material as the mixing region subassembly. During assembly, optical fibers are inserted into the mixing region subassembly which is then filled with a high index material to form a high-refractive index waveguide core region in the channel. The molded low-refractive index subassemblies provide a waveguide cladding around the high-refractive index waveguide core. Low cost is attained by utilizing optically finished metal molds to produce the subassemblies resulting in an optically finished mixing region and lid subassemblies without the need to polish each subassembly.

Abstract: An optical coupler using round optical fibers whose ends have been formed into a predefined shape to allow greater physical packing densities in order to achieve greater uniform illumination efficiency. The interstitial space between optical fibers is greatly reduced by thermoforming the ends of round optical fibers in a mold that makes a gradual transition from a circular shape to the predefined shape to avoid optical loss. Since the change in shape is gradual, the total cross-sectional area of the fibers remains constant; and optical loss is minimal becuase there is no reduction in mode volume. The predefined shape may be substantially square or rectangular. The core and cladding materials of the optical fiber are carefully chosen with respect to the glass transition state temperatures of both materials because the temperature at which the materials are formed by a mold are slightly above the glass transition state of the core or cladding, whichever is higher.

Abstract: A time slot converter for communicating multi-rate data on a single channel by using multiple time slots. By utilizing multiple replications of the time slot converter, any size time division switching unit such as time slot interchangers or time multiplexer switches may be assembled. The time slot converter has a plurality of switching elements and a switching element uses a time accounting arrangement that has the same overhead in assigning multiple time slots to a channel as in assigning one time slot to a channel. The switching element requires less buffer storage because each time slot has only one bit, and it is not necessary to store multiple frames. In addition, switching delay is reduced, since the delay due to buffering is always less than a frame period. Data order is maintained by using time slots for high capacity channels that are equally spaced in time and whose order is guaranteed.

Abstract: A method for fabricating a high efficiency optical coupler by matching the emerging light exit pupil from a coupler opening to the acceptance shape of a couple optical fiber. An excimer laser forms the coupler opening in an optical fiber by removing cladding from the optical core surface. The coupler opening has an elliptical shape resulting in an emerging light exit cone, and that exit cone matches an acceptance cone of a circular coupler optical fiber.

Abstract: A method for fabricating optical components in the cladding of an optical fiber bus by the utilization of a laser. An excimer laser fabricates either an optical coupler opening or an optical mode scrambler by ablatively removing the cladding from the optical core of an optical fiber bus without damaging the optical core. Either coupler housing or a mode scrambler housing is attached to the optical fiber bus where the coupler or mode scrambler is to be fabricated. The coupler housing is used to position the laser, secure and align a coupler fiber, and provide cavities for junction and cladding repair materials. The mode scrambler housing serves a similar purpose.

Abstract: An optical coupler having an optical core in which a small concentration of refractive microparticles has been added to a suspension material of the optical core. The result is that light from an optical source is bent slightly by the refractive effects of the microparticles and is coupled into the higher order of modes over a relatively short distance within the optical core. These microparticles are closely matched to the index of refraction of the suspension material resulting in smaller deflection angles and fewer reflections. In addition, these microparticles match the specific gravity of the suspension material such that they do not settle out of a suspension while the optical core material is being hardened from a semi-liquid state.

Abstract: A cladding portion (15) of an optical fiber (16) is laser machined by focusing a laser beam (13) that is of an appropriate wavelength to ablate the cladding. When the laser beam completely penetrates through the cladding (15) to impinge on the optical fiber core (18) light is transmitted to the two ends of the fiber. A photodetector (31) is placed in close proximity to one of the ends of the optical fiber (16) with the photodetector output being connected to a laser control device (23). When the light detected by the detector exceeds a threshold, it generates a signal that stops the laser. Even if the cladding is of an unpredicted thickness, the laser beam is not terminated until there has been complete penetration through the cladding, and after complete ablation the laser beam is promptly terminated so as to avoid subsequent damage to the optical fiber.

Abstract: An apparatus for automatically adjusting the optical power output of multiple optical transmitters. Each of the optical transmitters is optically interconnected to a common optical repeater. The optical repeater is responsive to optical signals received from each optical transmitter to adjust the optical output levels of these optical transmitters to a common level by transmitting signals back to the optical transmitters. The optical repeater commences the adjustment procedure upon detection that one or more of the optical transmitters is transmitting above or below a predefined power level.

Abstract: Apparatus that allows a called party, while engaged in a first call, to indicate to a second calling party that he/she is aware of the second call and will respond to the second call within a waiting time interval. The second calling party is given a "personal answer" message indicating that the called party will answer the second call within the waiting time interval. The second calling party is then placed on hold so that when the called party terminates the first call, the called party can answer the second call.

Abstract: Apparatus for controlling the transition of a number of lasers that are transmitting light to an optical bus from an off state to a sub-threshold bias state so as to minimize the transmission of light from lasers in the sub-threshold bias state. The apparatus places each laser in the sub-threshold bias state a predetermined time before it is to transmit data to the bus; and then, the apparatus places each laser in the off state after the data transmission has occurred. The lasers transmit in a sequential order onto the optical bus.

Abstract: A method for fabricating a high efficiency optical coupler by matching the emerging light exit pupil from a coupler opening to the acceptance shape of a coupler optical fiber. An excimer laser forms the coupler opening in an optical fiber by removing cladding from the optical core surface. The coupler opening has an elliptical shape resulting in an emerging light exit cone and that exit cone matches an acceptance cone of a circular coupler optical fiber.

Abstract: An apparatus for fabricating optical fiber mode scramblers and optical fiber couplers as an integral part of an optical bus by the utilization of a laser to remove cladding on the optical fiber bus to form the mode scramblers and couplers. An excimer laser is utilized to ablatively remove the cladding which is a polymer material. The optical core is composed of a material which is not readily affected by the excimer laser. The optical bus is fabricated by enclosing an optical fiber in an optical bus assembly. The optical fiber has only cladding and an optical core and has no buffer surrounding the cladding. The optical bus assembly provides for a plurality of optical couplers for removing and adding light to the optical bus and intermixed with the optical coupler are a plurality of optical scramblers.

Abstract: An optical splitter/combiner having an adiabatic mixing region for optically interconnecting a plurality of optical fibers. The change in shape of the adiabatic mixing region is purposely gradual so as to introduce little optical loss. The shape of the adiabatic mixing region is varied so as to minimize the change in the cross-sectional area of the adiabatic mixing region. The optical splitter/combiner is fabricated by the utilizing two subassemblies which when fitted together form the adiabatic mixing region. This formed mixing region is adapted to accepting a linear array of optical fibers in one end and a single optical fiber in the other end. The core area of the optical fibers in one end is not necessarily equivalent to those of the other end but instead are sized to ensure the relatively efficient transfer of optical energy. The adiabatic mixing region is filled with resin, and the numerical apertures of the optical fibers and the resin-filled mixing region are substantially matched.

Abstract: An excimer laser fabricates either an optical coupler opening or an optical mode scrambler by ablatively removing the cladding from the optical core of an optical fiber bus without damaging the optical core. Either coupler housing or a mode scrambler housing is attached to the optical fiber bus where the coupler or mode scrambler is to be fabricated. The coupler housing is used to position the laser, secure and align a coupler fiber, and provide cavities for junction and cladding repair materials. The mode scrambler housing serves a similar purpose.

Abstract: An optical splitter having a self-contained optical source with the optical core of the splitter being substantially numerical aperture matched to the optical source and to optical fibers connected to the splitter. By matching numerical apertures, efficient transfer of optical energy is achieved between the optical source and the connected optical fibers in spite of refractive index mismatch between the optical core and the connected optical fibers. The splitter is fabricated by inserting the optical source and optical fibers into a rigid cladding structure and filling the rigid cladding structure with a polymer which after curing becomes an optical core for communicating light from the optical source to the optical fibers.

Abstract: A mode scrambling arrangement for a multimode optical fiber by irradiating the cladding using an ultra-violet light to change the index of refraction of the cladding. The cladding uses a material whose index of refraction is modified in response to ultra-violet light. The exposure time and intensity of the light required is determined by monitoring the mode pattern in the multimode fiber during the irradiation to provide the desired amount of mode scrambling.

Abstract: A modular, substantially infinitely-growable, multi-node switching system operates under distributed control to serve integrated circuit-switched and packet-switched traffic at the data rates appropriate for each type of traffic. The system comprises a plurality of interconnected identical switching units that form at least one communication switching node. A communication switching node is a modular building block of the system; a switching unit is a modular building block of a switching node, and hence also of the system. A plurality of communication endpoint nodes--illustratively PBXs--is connected to the one or more switching nodes for communicating with each other through the switching nodes. A plurality of communication links each connect a different one of the system's switching units to either (a) one of the communication endpoint nodes or (b) a unit of another switching node. All of the links have the same communication format.

Abstract: A relatively inexpensive and relatively efficient coupler is obtained by connecting two fiber collections with a polymer material, provided the numerical aperture of the two collections are relatively well-matched to each other and to the polymer region. This efficiency is achieved despite relatively large mismatches in the refractive index of the resin material relative to the fibers. Couplers for optical backplanes are produced in one embodiment utilizing plastic materials. In this technique, a collection of fibers is inserted on each end of an enclosure such as a tube that is filled with a polymer that is subsequently cured.

Abstract: A non-invasive optical fiber coupler for coupling light into an optical fiber bus through the cladding surrounding the optical fiber bus without bending the optical fiber bus. The coupler comprises a tap optical fiber free end adjacent to and facing a region of straight optical fiber bus with the tap fiber free end and optical fiber bus region encapsulated with a junction media having substantially the same index of refraction as the cladding of the optical fiber bus. Since the bus cladding is not removed nor is the optical fiber bus bent, there is no additional light lost due to the coupler from the optical fiber bus.