100-Mbit/s LED-p-i-n transmitter and receiver modules for high-speed local area networks

100-Mbit/s fiber-optic transmitter and receiver modules using a 1.3-μm light-emitting diode (LED)-p-i-n combination are developed for computer-link applications. The use of a dc-balanced coding scheme is desirable in such applications from the viewpoint of improving the transient response of the system. A modified duobinary class-II coding scheme is applied as a transmission code. Four monolithic integrated circuits, that is, a preamplifier, an automatic-gain-controlled (AGC) amplifier, regenerator, and LED driver, are developed and confirmed to be useful for realizing highly reliable compact modules. These modules are tested using a standard graded-index fiber. An allowable span loss of 12.4 dB is achieved at an error rate of 10^-12. The degradation due to the data pattern transients from 1/12 to 11/12 is negligibly small. Total power consumption of modules is a 1.4-W/module pair with a 5-V single power supply.