Patent ID: 8165475

Claim:
A system for reducing clipping in a modulated optical system, the system comprising: a laser including an RF input configured to receive a multichannel RF signal, a bias input configured to receive a bias current, and an optical output to provide a modulated optical signal in response to the multichannel RF signal and the bias current, the multichannel RF signal including a superposition of multiple modulated carriers and occupying a bandwidth across a range of frequencies of the multiple modulated carriers; enveloper follower circuitry configured to receive the multichannel RF signal and to detect an envelope of the multichannel RF signal without upconverting the multichannel RF signal, wherein the detected envelope follows peaks in the RF signal including peaks above and below a clipping threshold; and bias control circuitry coupled to the envelope follower circuitry and to the bias input of the laser, the bias control circuitry being configured to vary the bias current provided to the laser diode in response to a level of the detected envelope of the multichannel RF signal such that the bias current is continuously varied to follow the detected envelope and at least one negative voltage spike in the RF signal is prevented from causing clipping in the laser.