Patent ID: 8355199

Claim:
An optical filter, comprising: a first whispering gallery mode resonator filter adapted to receive at least a portion of a first optical signal including an optical carrier frequency and a plurality of interference signal spectral components, the first filter producing an output signal at the optical carrier frequency, the output signal split into a peak detection path signal and a re-insertion path signal; an optical power detector adapted to receive the peak detection path signal and convert the peak detection path signal into an electrical control signal representative of a power of the optical carrier frequency, wherein the control signal is adapted to align the optical carrier frequency to a resonance frequency of the first filter to maximize the power of the optical carrier frequency; a second whispering gallery mode resonator filter adapted to receive at least a portion of the first optical signal and to select at least one spectral component in the first optical signal while rejecting other spectral components and to output a filtered signal that carries the at least one selected spectral component; and a signal combiner that receives and combines the filtered signal and the re-insertion path signal.