Abstract: Improved dispersion compensating circuits for optical transmission systems are disclosed. According to the improved method, there is provided a compensation circuit comprising a varactor diode network. The network is preferably inserted between a source of laser modulating signal and the laser. A low-pass filter or all pass filter constructs the network. The network preferably includes an inductor or inductors and a combined circuit, which includes varactors. The network preferably provides an amplitude dependent delay of the modulating signal applied to the laser or to the optical receiver as post dispersion correction circuitry. In a first embodiment, a fixed capacitor is in series with a varactor and connected to a DC bias through inductor. Additional embodiments, using multiple varactors in different circuit configurations, with particular advantages for various applications identified.

Abstract: Improved dispersion compensating circuits for optical transmission systems are disclosed. According to the improved method, there is provided a compensation circuit comprising a varactor diode network. The network is preferably inserted between a source of laser modulating signal and the laser. A low-pass filter or all pass filter constructs the network. The network preferably includes an inductor or inductors and a combined circuit, which includes varactors. The network preferably provides an amplitude dependent delay of the modulating signal applied to the laser or to the optical receiver as post dispersion correction circuitry. In a first embodiment, a fixed capacitor is in series with a varactor and connected to a DC bias through inductor. Additional embodiments, using multiple varactors in different circuit configurations, with particular advantages for various applications identified.

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.