Patent ID: 8554085

Claim:
A frequency-modulated spread spectrum waveform generator comprising: (a) a generator for generating a frequency modulated optical waveform; (b) a comb generator for generating an optical comb; (c) an optical coupler combining frequency modulated optical waveform and the optical comb; and (d) at least one photodetector for heterodyning the output of the optical coupler wherein the comb generator comprises multiple loops including: (i) a first optical delay line in a first loop for spacing a comb generated by the multi-tone optical comb generator; (ii) a second optical delay in a second loop line for noise reduction, the second delay line being longer than the first optical delay line; (iii) at least one photo detector connected to the first and second delay lines; and (iv) an optical intensity modulator in a loop portion common to the first and second loops for driving the first and second optical delay lines.