Patent ID: 8050558

Claim:
An optical signal sampling apparatus comprising: a sampling light pulse generating unit which generates a sampling light pulse having a predetermined period to sample an optical signal to be sampled; and an optical sampling unit which samples the optical signal to be sampled, with the sampling light pulse from the sampling light pulse generating unit and emits an optical pulse signal obtained by the sampling, wherein the optical sampling unit includes: an optical combiner which combines the optical signal to be sampled and the sampling light pulse from the sampling light pulse generating unit with each other; an electroabsorption modulator having two optical terminals for inputting/outputting light and a power supply terminal for applying an electric field to an optical path connecting the two optical terminals, the electroabsorption modulator having such a characteristic that an absorption rate of the light propagating through the optical path is changed in accordance with the magnitude of the electric field, one terminal of the two optical terminals receiving the light emitted from the optical combiner; a DC power supply which applies, to the power supply terminal of the electroabsorption modulator, a predetermined DC voltage for sampling the optical signal to be sampled, with the sampling light pulse in the electroabsorption modulator by increasing the absorption rate in the absence of the sampling light pulse incident to the electroabsorption modulator and decreasing the absorption rate in the presence of the sampling light pulse incident to the electroabsorption modulator, thereby emitting an optical signal obtained by the sampling from another terminal of the two optical terminals; and an optical separator which selectively emits an optical signal component to be sampled, of the optical signal emitted from the other terminal of the two optical terminals of the electroabsorption modulator.