Low cost flexible automated optical power management

Abstract

Circuits and systems for use in monitoring and adjusting an optical signal strength of an optical data transmission system. A closed feedback loop which automatically controls an optical device's output uses an analog operational amplifier based circuit instead of a conventional microprocessor that uses complex calculations. The parameters of the operational amplifier circuit are monitored and controlled by a microcontroller to provide flexible operational settings. The analog circuit containing discrete analog components is used as a power meter for measuring an optical power signal strength of an optical signal. The optical signal is tapped by an optical coupler and the signal is received by a photodetector. The output of the photodetector is received by the analog circuit which produces an intermediate signal based on the level of optical power in the optical signal. The intermediate signal is used to control an optical device. Since the operating parameters of some of the analog components in the analog circuit may be controlled by the microcontroller, the analog circuit may therefore be calibrated or adjusted by the microcontroller. This allows one to take advantage of the speed of analog component based circuits while keeping the flexibility and communications capability of a digital circuit such as a microcontroller.