Patent ID: 8842992

Claim:
A communications device comprising: a transmitter device comprising an optical source configured to generate an optical carrier signal, a first electro-optic (E/O) modulator coupled to said optical source and configured to modulate the optical carrier signal with an input signal having a first frequency, a second E/O modulator coupled to said optical source and configured to modulate the optical carrier signal with a reference signal, a first band pass filter coupled downstream from said first E/O modulator and configured to pass a carrier frequency sideband, and a second band pass filter coupled downstream from said second E/O modulator; an optical waveguide coupled to said transmitter device; and a receiver device coupled to said optical waveguide and comprising an O/E converter coupled to said optical waveguide and configured to generate an output signal comprising a replica of the input signal at a second frequency based upon the reference signal; said second band pass filter configured to pass a reference signal frequency sideband at a greater frequency than that of the carrier frequency sideband when the second frequency is greater than the first frequency, and pass the reference signal frequency sideband at a lesser frequency than that of the carrier frequency sideband when the second frequency is less than the first frequency.