Patent ID: 7330670

Claim:
A burst mode optical receiver comprising a bottom level detection device, a converter configured to convert a burst mode signal into a voltage signal and an automatic gain controller configured to automatically control a gain of the converter, said bottom level detection device being configured to detect a bottom level of an output signal from the converter and configured to control the automatic gain controller on the basis of the detected bottom level, said bottom level detection device comprising: a differential amplification means configured to receive the output signal from the converter at its first input terminal and a fed-back output signal from said bottom level detection device at its second input terminal, respectively, and configured to amplify a difference between the received signals; a detection means configured to detect a bottom level of an output signal from said differential amplification means; and an output buffering means being configured to output the fed-back output signal from said bottom level detection device, a power level detector that is configured to detect a power level of the voltage signal output from said differentia 1 amplifications means, said power level detector being configured to determine whether an input signal to the receiver is present and whether an inter-packet period is present; wherein said detection means includes an RC rectifier that is configured to receive a power supply voltage, and a transistor having its emitter connected to an output terminal of said differential amplification means and its base and collector connected in common to said RC rectifier; and reset means for providing an independently generated initial reset signal, said reset means comprising a plurality of pulse generators driven by an output of said power level detector and said detection means for detecting a bottom level of the output signal from said differential amplification means.