Automatic bandwidth control system

Claim 1

An automatic bandwidth control system for an adaptive optics servo comprising in combination: a bandpass filter means receiving a photodetected signal, said bandpass filter means removing unwanted high and low signals, said bandpass filter means maintaining a predetermined signal level, a gain parameter means receiving the output signal from said bandpass filter means, said gain parameter means multiplying said output signal by a gain parameter to provide a gain correction signal, a modulation means operating at a dither frequency, ω g , said modulation means providing a modulation signal, a multiplier means receiving said gain correction signal and said modulation signal, said multiplier means providing a DC gain correction signal, a low pass filter means receives and filters said DC gain correction signal to remove noise and unwanted signals, a first limiter means receives said DC gain correction signal from said low pass filter means to maintain the signal within predetermined limits, a gain source provides a gain factor that is added to said DC gain correction signal to provide a gain signal, a second limiter means receives said gain signal and limits said gain signal to a predetermined level, a gain modulation means receives said modulation signal, said gain modulation means multiplies said modulation signal by an amplitude factor to provide a dither signal, and an adder means receives and adds together said dither signal and said gain signal to provide a bandwidth correction signal.