Patent ID: 8401808

Claim:
A wavelength-multiplexed optical signal measurement device comprising: a sequentially sampled electrical field sampling unit that measures a total electrical field amplitude of a wavelength-multiplexed optical signal; and a sequentially sampled electrical field analyzing unit that applies Fourier analysis to a result of the measurement carried out by the sequentially sampled electrical field sampling unit, and calculates an electrical field amplitude of a signal component of each wavelength, the sequentially sampled electrical field sampling unit measuring the total electrical field amplitude J m of the wavelength-multiplexed optical signal M times at intervals of time T, where a total bandwidth of the wavelength-multiplexed optical signal is Δf total , the time T is set shorter than 1/Δf total , and the inverse number 1/(MT) of a total observation time is set smaller than a frequency interval Δf of an adjacent wavelength channel, the sequentially sampled electrical field analyzing unit calculating an amplitude of a signal of each wavelength by determining a series of Fourier transformations of the total electrical field amplitude J m (0≦m≦M−1) determined by the sequentially sampled electrical field sampling unit.