Abstract: A fiber array unit (200) and a photonics system (890), a fiber array unit (200) comprises a substrate (205) with a first el end and a second end. A first mesa (207) is adjacent to the first end and a second mesa (209) is adjacent to the second end. A v-groove (211) is in the first mesa (207) and a slot (213) is in the second mesa (209). The v-groove (211) is aligned with the slot (213).

Abstract: An optical receiver signal strength indicator (RSSI) circuit for use in an optical receiver or transceiver module is provided that uses a variable impedance device in the supply voltage filter circuit. The variable impedance device is varied based on the strength of the input current signal produced by the photodiode. At lower values of input current, the variable impedance is increased to improve the accuracy with which the RSSI circuit senses the input current, which improves the accuracy of the RSSI signal output from the RSSI circuit. The increase in impedance also improves supply voltage filtering by reducing the low-pass bandwidth of the supply voltage filter circuit. At higher values of input current, the variable impedance is decreased to ensure that the voltage bias applied to the photodiode is at least equal to a minimum bias voltage needed for proper operation of the photodiode.

Abstract: In one exemplary embodiment, an optical communications module includes an upper housing portion mated to a lower housing portion with an optical port projecting through an opening in a front surface of the mated assembly. Electronic circuit housed inside the mated assembly can lead to electromagnetic interference (EMI) leakage through a front surface of the mated assembly, especially through the opening that accommodates the optical port. An EMI shield, which is used to address the EMI leakage, includes an annular array of resilient metal fingers that press against a metal flange of the optical port, and also includes at least two peripheral edges each incorporating an array of resilient metal fingers that press against a metal portion of the mated assembly. An interdigital spacing in the annular array and/or the array of resilient metal fingers is defined on the basis of a wavelength associated with the EMI radiation.

Abstract: An optical receiver signal strength indicator (RSSI) circuit for use in an optical receiver or transceiver module is provided that uses a variable impedance device in the supply voltage filter circuit. The variable impedance device is varied based on the strength of the input current signal produced by the photodiode. At lower values of input current, the variable impedance is increased to improve the accuracy with which the RSSI circuit senses the input current, which improves the accuracy of the RSSI signal output from the RSSI circuit. The increase in impedance also improves supply voltage filtering by reducing the low-pass bandwidth of the supply voltage filter circuit. At higher values of input current, the variable impedance is decreased to ensure that the voltage bias applied to the photodiode is at least equal to a minimum bias voltage needed for proper operation of the photodiode.

Abstract: A wavelength division multiplexing/demultiplexing optical transceiver module is provided that is suitable for use in single mode optical fiber (SMF) and multimode optical fiber (MMF) optical communications links. When used in an MMF optical communications link, the optical transceiver module allows the length and bandwidth of the link to be increased significantly. The optical transceiver module can be used advantageously in an MMF link that includes existing MMF infrastructure to increase the bandwidth of the MMF link while avoiding the costs associated with pulling new higher-bandwidth fiber.

Abstract: A ferrule of an optical communications module is allowed to float to a limited degree within the module housing. Consequently, if a force is exerted on the connector that mates with the optical communications module, the mated ferrules of the module and of the connector moves, or floats, within defined limits so that the ferrules move together rather than relative to one another. In this way, the end faces of the ferrules remain in precise alignment to prevent wiggle losses from occurring due to movement of the connector relative to the module housing.

Abstract: A ferrule of an optical communications module is allowed to float to a limited degree within the module housing. Consequently, if a force is exerted on the connector that mates with the optical communications module, the mated ferrules of the module and of the connector moves, or floats, within defined limits so that the ferrules move together rather than relative to one another. In this way, the end faces of the ferrules remain in precise alignment to prevent wiggle losses from occurring due to movement of the connector relative to the module housing.

Abstract: In one example embodiment, an optoelectronic communications assembly having an optical receiver or an optical transmitter includes an optical interface disposed at an end thereof and through which optical signals are communicated by the optical receiver or optical transmitter. The optoelectronic communications assembly also includes an electronic component and a first electrical interface disposed at the optical interface end of the optical communications assembly and communicatively coupled to the electronic component.

Abstract: Provided herein is a novel approach to simultaneous fiber presence detection and improved laser eye safety of an optical transceiver. The subject optical transceiver is fitted with at least one switch in its receptacle that controls the laser diode and indicates the presence of a fiber (or fibers) within such a receptacle. If a fiber is present within the subject module receptacle, the laser switch is permitted to be “on”, whereas the absence of a fiber will prevent the laser switch from turning on, thereby permitting effective control of the laser at a single point of failure within the entire optical transceiver system. The typical optical transceivers of today exhibit limited optical power output due to eye safety limit criteria.

Abstract: An optical transmitter is disclosed wherein a signal processor receives a data stream and outputs a drive signal for a laser, where the drive signal encodes each bit of the data stream according to the values of adjacent bits effective to compensate for spreading of bits within the fiber. The output of the laser is input to an optical spectrum reshaper that outputs a signal having an enhanced extinction ratio.

Abstract: In one example embodiment, an optoelectronic communications assembly having an optical receiver or an optical transmitter includes an optical interface disposed at an end thereof and through which optical signals are communicated by the optical receiver or optical transmitter. The optoelectronic communications assembly also includes an electronic component and a first electrical interface disposed at the optical interface end of the optical communications assembly and communicatively coupled to the electronic component.

Abstract: A latching system for use in selectively securing a module within a receptacle of a host device is described. In one or more examples, the latching system includes a powered actuation mechanism and a latching mechanism. In one or more examples, the module latching mechanism includes a latch and the powered actuation mechanism disengages a latch from a catch. In one or more examples, two latches are provided. In one or more examples, the latching mechanism of a module includes a pusher that interacts with a latch located on a receptacle. In one or more examples, a module includes two latches.

Abstract: An optical transmitter is disclosed wherein a signal processor receives a data stream and outputs a drive signal for a laser, where the drive signal encodes each bit of the data stream according to the values of adjacent bits effective to compensate for spreading of bits within the fiber. The output of the laser is input to an optical spectrum reshaper that outputs a signal having an enhanced extinction ratio.

Abstract: A latching system for use in selectively securing a module within a receptacle of a host device is described. In one or more examples, the latching system includes a powered actuation mechanism and a latching mechanism. In one or more examples, the module latching mechanism includes a latch and the powered actuation mechanism disengages a latch from a catch. In one or more examples, two latches are provided. In one or more examples, the latching mechanism of a module includes a pusher that interacts with a latch located on a receptacle. In one or more examples, a module includes two latches.

Abstract: A relatively small, pluggable optical transceiver utilizes a set of at least three separate printed wiring boards (PWBs), coupled together with a pair of flexible wiring boards, allows for the “middle” (base) PWB to be disposed in a horizontal plane, with the PWBs on either side (i.e., a transmitter PWB and a receiver PWB) to be disposed parallel to the base PWB, by virtue of using the flexible PWBs. Advantageously, the optoelectronic transmitter and receiver modules are directly connected (hardwired) to their respective, vertical PWBs, to form a rugged arrangement. Crosstalk between the vertical boards is reduced by using a shielding plate between the boards. Undesired fiber movement is reduced (as compared to the prior art) by separating the optical path from the electrical path, which also provides mechanical relief for the transmitter and receiver PWBs.

Abstract: Output optical power of an optical transmitter is regulated to compensate for fluctuations in output optical power and for tracking error. Dual loop automatic power control includes an optical sensor feedback loop for sensing optical energy proximate a back facet of the optical transmitter and a thermal sensor feedback loop for sensing thermal energy at point proximate the optical transmitter. Fluctuations in sensed thermal energy are indicative of the tracking error of the optical transmitter. Signals indicative of the sensed optical and thermal energy are combined and utilized to regulate the output optical power to be approximately constant over a predetermined range of temperatures.

Abstract: A transceiver and method of fabrication where the housing comprises a carrier upon which the source and photodetector are mounted and a cover. The housing includes an integral wall extending between the source and photodetector so as to electrically isolate the two devices. The cover may physically contact the wall to provide grounding for the cover.