摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. In a further alternate embodiment, a FET is coupled to the p-i-n photodiode to form an integrated detector preamplifier along with the VCSEL transmitter all on the same optical reference plane.
摘要:
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. The photodetector system may also employ a peak detector capacitor discharge circuit where a large capacitance is simulated by having the capacitor discharge through the base of a transistor have a current source in the emitter circuit.
摘要:
A method for making a transmitter optical subassembly (TOSA) is provided. In the method, an alignment in the Z-direction between a fiber stub array (FSA) and a VCSEL array is performed first. Then, an alignment in the X-Y direction is performed. A rough prealignment in the X-Y direction may also be performed prior to the alignment in Z-direction. A vertical cavity surface emitting laser (VCSEL) array may be hermetically sealed using a lens assembly or by using a separate lid assembly. The hermetic sealing and attaching of different components may be achieved by laser welding and/or soldering or any other suitable method.
摘要:
An opto-electronic device configured as a photodetector has a capacitor and/or resistor monolithically formed on a surface of the photodetector. The capacitor capacitively couples the AC ground of the photodetector to the bias terminal of the photodetector. The on chip capacitor design eliminates the inductance of external circuit traces between the power supply and an external capacitor. The resistor forces the AC return current of the photodetector through the AC ground in preference to the typical (DC bias terminal) path. Combinations of capacitors and resistors are particularly effective in reducing crosstalk among adjacent detectors in arrays.
摘要:
Selectively oxidized vertical cavity lasers emitting at about 1290 nm using InGaAsN quantum wells that operate continuous wave below, at and above room temperature are reported. The lasers employ a semi-insulating GaAs substrate for reduced capacitance, high quality, low resistivity AlGaAs DBR mirror structures, and a strained active region based on InGaAsN. In addition, the design of the VCSEL reduces free carrier absorption of 1.3 μm light in the p-type materials by placing relatively higher p-type dopant concentrations near standing wave nulls.
摘要:
A pluggable optical transceiver having a having a slidable actuator assembly for quickly and easily removing the transceiver from a receptacle cage assembly is provided. The actuator assembly includes a curved actuator handle and slide member that can slide in a forward and rearward direction. As force is exerted on slide member, the actuator and slide member slide rearwardly causing the transceiver to become disengaged from the receptacle. In this manner, the transceiver is released and can be removed easily from the receptacle.