Patent Document ID: 7873272
Application ID: 11559015
Patent Flag: 1

Claim One:
1. A method of optical signal monitoring, comprising the steps of: modulating, using an optical modulator, the optical phase of pulses in a pulse train using a periodic waveform having an amplitude to generate a modulated signal; and generating two derivatives of a spectrum of the modulated signal with respect to said amplitude sampling each of the spectrum derivatives at frequency points separated from one another by a frequency of the periodic waveform to generate a plurality of sample values; generating a series of complex values, wherein, for each of said complex values, the real part is a respective sample value of one of the spectrum derivatives and the imaginary part is a corresponding sample value of the other spectrum derivative; and calculating an optical phase profile in the frequency domain for the pulses in the pulse train based on the phase of a complex value obtained by summing a plurality of complex values from the series.