Abstract: A receiver assembly for use in an optical telecommunications network is provided that automatically generates a reference level for the incoming signal burst based on its preamble without the need to pre-process the entire signal burst. The entire signal burst is fed directly from the TIA into the input of the limiting amplifier. A differential amplifier, tapped from the data and data bar outputs of the limiting amplifier, samples the signal stream to capture the preamble portion of each signal burst. The preamble portion of the signal burst is then passed, post amplification, into a sample and hold circuit. The sample and hold circuit samples the amplitude of this preamble portion of the signal and then holds the sampled level for use as a reference level for the processing of following payload signal.

Abstract: A laser transmitter within an optical transceiver includes a heating element. The heating element is coup led to the laser package and is controlled to allow the laser to be heated to a higher temperature than the ambient temperature when low environmental temperature extremes occur. The transmitter includes a semiconductor laser having an optimal operational temperature range, a laser driver circuit coupled to the laser that provides a modulation current and a bias current to drive the laser, a heating element thermally coupled to the laser and a heating control circuit that monitors the bias current applied to the laser for drops in bias current that are indicative of drops in the surrounding ambient temperature. In response to a drop in bias current, the control circuitry energizes the heating element to provide heat to the laser.

Abstract: A receiver assembly for use in an optical telecommunications network is provided that automatically generates a reference level for the incoming signal burst based on its preamble without the need to pre-process the entire signal burst. The entire signal burst is fed directly from the TIA into the input of the limiting amplifier. A differential amplifier, tapped from the data and data bar outputs of the limiting amplifier, samples the signal stream to capture the preamble portion of each signal burst. The preamble portion of the signal burst is then passed, post amplification, into a sample and hold circuit. The sample and hold circuit samples the amplitude of this preamble portion of the signal and then holds the sampled level for use as a reference level for the processing of following payload signal.

Abstract: A VCSEL is provided that integrates an absorbing layer sandwiched within a null of the standing wave in the emitting mirror to reduce the reflectivity and transmissivity of the emitting mirror as seen by the feedback optical wave, with minimal effect on the reflectivity of the emitting mirror as seen by the light exiting the cavity. The absorbing layer may be made of a suitable absorbing material, such as a GaAs layer in a laser emitting near 850 nm or highly doped p-layer, for instance, and may be disposed epitaxially in a semiconductor or metamorphic mirror. The absorbing layer sandwich may be incorporated into the VCSEL after the last mirror pair or at any desired position with the emitting mirror array.

Abstract: In an exemplary embodiment of the present invention, an optical interface unit provides an interface between an optoelectronic device and industry standard MTP/MPO connectors. The optical interface unit axially aligns the core of a fiber with the optoelectronic device and interfaces that fiber to the standardized connector. In addition, the optical interface unit further provides a standardized interface for visible contact connection between the individual fiber stubs and the terminated fibers in the standardized connector. The optical interface unit therefore maximizes coupling from the optoelectronic device with the standardized connector.

Abstract: A method and apparatus for driving lasers. An example laser driving system includes a laser current controller for providing a modulation signal and a bias signal. The modulation signal and bias signal is used by a plurality of high-speed current drivers that accept the modulation signal and the bias signal and produce a plurality of laser drive signals. The example system also has a disable input that disconnects power from a high-speed current driver when the high-speed current driver is not in use. The exemplary system develops the modulation and bias signals by feeding back a signal developed from detection of laser light from one of the lasers driven by the system. The laser may be a data laser or a control laser that is modulated by a signal having a lower frequency than the data lasers. If a control laser is used then the photodetector circuit used for feedback can have a lower frequency response because of the lower frequency of the control laser signal.

Abstract: A laser transmitter within an optical transceiver includes a heating element. The heating element is coup led to the laser package and is controlled to allow the laser to be heated to a higher temperature than the ambient temperature when low environmental temperature extremes occur. The transmitter includes a semiconductor laser having an optimal operational temperature range, a laser driver circuit coupled to the laser that provides a modulation current and a bias current to drive the laser, a heating element thermally coupled to the laser and a heating control circuit that monitors the bias current applied to the laser for drops in bias current that are indicative of drops in the surrounding ambient temperature. In response to a drop in bias current, the control circuitry energizes the heating element to provide heat to the laser.

Abstract: In an exemplary embodiment of the present invention, an optical interface unit provides an interface between an optoelectronic device and industry standard MTP/MPO connectors. The optical interface unit axially aligns the core of a fiber with the optoelectronic device and interfaces that fiber to the standardized connector. In addition, the optical interface unit further provides a standardized interface for visible contact connection between the individual fiber stubs and the terminated fibers in the standardized connector. The optical interface unit therefore maximizes coupling from the optoelectronic device with the standardized connector.

Abstract: A self-adjusting data transmitter driver can be used for transmission of analog or digital data signal over any suitable communication channel, such as, for example, optical, electrical, wireless and satellite. The optical transmitter driver may be used to drive a single laser as well as an array of lasers. An optical transmitter driver including a laser diode driver can be used to provide modulation and bias currents to drive a laser diode in an optical communication system. A high speed photodiode is used to monitor high frequency characteristics of the optical data signal while one or more photodiodes are used to detect source parameters of the optical data signal. To compute the feedback parameters, parameters including BER, data-eye, discrete optical data integrity parameters and discrete optical parameters are determined using the feedback detectors. The feedback parameters are used to adjust the optical quality of the laser output towards optimization.

Abstract: A fiber optic module that includes a packaged integrated circuit chip mounted on a top surface of a printed circuit or other mounting board is disclosed. The integrated circuit chip is electrically coupled to an optical subassembly (OSA) mounted along an edge of the printed circuit board and capable of emitting or receiving light traveling parallel to the printed circuit board. The packaged IC chip is electrically coupled to the OSA through at least one microwave via extending through the board and a conductive trace formed on the opposed bottom surface of the board.

Abstract: In an exemplary embodiment of the present invention, an optical interface unit provides an interface between an optoelectronic device and industry standard MTP/MPO connectors. The optical interface unit axially aligns the core of a fiber with the optoelectronic device and interfaces that fiber to the standardized connector. In addition, the optical interface unit further provides a standardized interface for visible contact connection between the individual fiber stubs and the terminated fibers in the standardized connector. The optical interface unit therefore maximizes coupling from the optoelectronic device with the standardized connector.

Abstract: Systems and methods for optical communication that may be employed to couple together fiber optic arrays of two or more optical communication modules using parallel fiber optic connectors and physically distinct and signal-independent optical communication paths. The disclosed systems and methods may be employed to provide separate signal-independent communication paths having signal transport characteristics that meet standards required for single fiber single point-to-single point applications.

Abstract: A method and apparatus for burning in a semiconductor wafer having a plurality of active devices utilizes temporary conductive interconnect layers to separately couple at least a portion of the anodes of the active devices together as well as at least a portion of the cathodes of the devices together. A simplified probed pad, having a reduced number of contacts may then be utilized to apply a substantially constant voltage or current to the devices. The temporary conductive interconnect layer may be patterned to include device level resistors or array level resistors that may be used to mitigate the effects of short circuits or open circuits on the processing of the devices.

Abstract: Systems and methods for optical communication that may be employed to couple together fiber optic arrays of two or more optical communication modules using parallel fiber optic connectors and physically distinct and signal-independent optical communication paths. The disclosed systems and methods may be employed to provide separate signal-independent communication paths having signal transport characteristics that meet standards required for single fiber single point-to-single point applications.

Abstract: A multilayer ceramic carrier for an optical element includes a terraced cavity for retaining a vertically receiving or vertically emitting optical element. The multilayer ceramic carrier includes conductive traces interposed between the ceramic layers and which extend into the terraced cavity along the trenches formed in the cavity. A vertical cavity surface emitting laser or vertically receiving optical element is wire bonded to the conductive traces which extend into the cavity. In one embodiment, the terraced cavity of the multilayer ceramic carrier includes a VCSEL and photodetector therein, the photodetector capable of monitoring the output optical power of the VCSEL. The method for forming the multilayer ceramic carrier includes forming a plurality of layers of ceramic tape, joining the layers, then co-firing the stacked layers. The multilayer ceramic carrier is joined to a plastic optical housing which includes an aperture for securing an optical fiber.

Abstract: An optically transparent, hermetic coating is locally formed on die and other components already assembled in an existing nonhermetic structure. The local hermetic sealing of an OSA includes providing an OSA having at least one exposed optoelectronic component, and providing a paralene source. The method provides for positioning a mask between the paralene source and the OSA, the mask including an opening aligned with a first region of the OSA. The first region includes at least one of the exposed optoelectronic components. The paralene source is then caused to generate paralene such that a permanent paralene coating is deposited through the opening and on the first region of the OSA. The permanent paralene coating essentially hermetically seals the first region. The permanent paralene coating is chosen to be transparent to the wavelength of light emitted and/or used in the optical sub-assembly.

Abstract: An optical signal receiver system provides for five (5) signals, namely VCC, Ground, RPM (Receiver input Power Monitor), Data, and Data Bar outputs, using only the four external pins of a conventional TO-style can package. To provide for five signals on only four pins, two of the output signals are superimposed on each other in which one has a DC value (RPM) and one has an AC value (Data or Data Bar). Once the combined signal comes out of the TO can, the combined signal can be separated into two separate signals using a capacitor which blocks the DC signal (Data or Data Bar) and allows the AC signal to go through. The DC information is then extracted by filtering the AC information from the combined signal with a Current Sense Circuit.

Abstract: A monolithically integrated VCSEL and photodetector, and a method of manufacturing the same, are disclosed for applications where the VCSEL and photodetector require separate operation such as duplex serial data communications applications. A first embodiment integrates a VCSEL with an MSM photodetector on a semi-insulating substrate. A second embodiment builds layers of a p-i-n photodiode on top of layers forming a VCSEL using a standard VCSEL process. The p-i-n layers are etched away in areas where VCSELs are to be formed and left where photodetectors are to be formed. The VCSELs underlying the photodetectors are inoperable, and serve to recirculate photons which are not initially absorbed back into the photodetector. The transmit and receive pairs are packaged into a single package for interface to multifiber ferrules. The distance between the devices is precisely defined photolithographically, thereby making alignment easier.

Abstract: A multilayer ceramic carrier for an optical element includes a terraced cavity for retaining a vertically receiving or vertically emitting optical element. The multilayer ceramic carrier includes conductive traces interposed between the ceramic layers and which extend into the terraced cavity along the trenches formed in the cavity. A vertical cavity surface emitting laser or vertically receiving optical element is wire bonded to the conductive traces which extend into the cavity. In one embodiment, the terraced cavity of the multilayer ceramic carrier includes a VCSEL and photodetector therein, the photodetector capable of monitoring the output optical power of the VCSEL. The method for forming the multilayer ceramic carrier includes forming a plurality of layers of ceramic tape, joining the layers, then co-firing the stacked layers. The multilayer ceramic carrier is joined to a plastic optical housing which includes an aperture for securing an optical fiber.

Abstract: A pluggable optical transceiver module includes a housing with first and second ends, upper and lower surfaces, a channel and an opening slot formed thereon. A locking boss is slidably mounted within the housing and has a locking detent projecting therefrom and through the opening slot of the housing to engage an opening in a latching tab located in a receptacle cage. The locking boss also has a top end with an inclined surface, which is disposed within the channel of the housing. An actuator arm is slidably mounted within the channel of the housing and has an internal end with an inclined surface thereon. The inclined surface of the actuator arm cooperates with the inclined surface of the of the locking boss to free the locking detent from the latching tab of the receptacle cage when the actuator arm is moved within the channel of the housing.