Patent ID: 7301972

Claim:
An apparatus for storing optical pulses in an optical resonator as a superposition of pulses, comprising: a mode-locked laser generating optical pulses comprising a comb of frequencies within a frequency range, said mode-locked laser having a selectable center frequency of said optical pulses; an FM sideband modulator receiving said optical pulses and generating input pulses for said optical resonator having an FM sideband frequency relative to said center frequency; a detector for receiving reflected laser light at said FM sideband frequency and stored light exiting said optical resonator at a cavity frequency; and a controller monitoring deviations of said center frequency from a resonant frequency of said optical resonator and in response adjusting said center frequency to match said resonant frequency within a selected margin less than a cavity bandwidth of said optical resonator; wherein said controller includes a first servo path for obtaining an initial lock to said center frequency and a second servo path for reducing residual noise.