Patent ID: 7154665

Claim:
Apparatus, comprising: a nonlinear optical device (NOD) adapted to receive an optical input signal; a first optical filter coupled to an output of the NOD to produce a first filtered signal; a signal processor adapted to: measure optical power of the input signal; measure an optical power of the first filtered signal; and monitor signal quality of the input signal based on the optical power measurements; a first optical tap configured to provide the signal processor with a sample of the input signal; a second optical tap configured to provide the signal processor with a sample of the first filtered signal, wherein the signal processor is adapted to: measure optical power of each of said samples; and obtain the measurements of the optical power of the input signal and the first filtered signal based on the power measurements of said samples and characteristics of the first and second optical taps; and a continuous wave (CW) source coupled to the NOD, wherein: a light beam generated by the CW source is applied to the NOD together with the optical input signal; and the first optical tap samples the optical input signal before said input signal is combined with said light beam for the application to the NOD.