Electro-optic devices

摘要

An electro-optic device for stabilizing the output level of a Burrus-type light emitting diode (LED) utilizes a photodiode to monitor side emission from an active region of the LED. Side emission closely tracks top emission, which is launched into an output fiber. An electrical analog is derived from the monitored side emission and is applied in a feedback loop to control modulation level or bias current to the LED. In this way, peak optical output (for digital systems) or r.m.s. output and linearity (for analog systems) is stabilized. The monitoring photodiode and the LED may be spatially separate or may form a unitary structure.