Patent ID: 8098995
Filing Date: 2012-01-17
Classification: G01J,G02F

Abstract:
1. An optical signal synchronization sampling apparatus comprising: a sampling optical pulse generation unit which emits a sampling optical pulse having a period Ts different from a predetermined offset time ΔT to integral N multiplication of a clock period Tc of a data signal, the data signal modulating a sampling object optical signal; and an optical sampling unit which supplies an optical pulse signal obtained by performing synchronization sampling of the sampling object optical signal using the sampling optical pulse emitted by the sampling optical pulse generation unit, wherein the optical sampling unit includes: an electroabsorption optical modulator which has two optical terminals and a power supply terminal, the two optical terminals being used to input and output light, the power supply terminal imparting an electric field to an optical path connecting the two optical terminals, the electroabsorption optical modulator having a characteristic in which an absorption index is changed with respect to the light propagating through the optical path according to a level of the electric field, the electroabsorption optical modulator receiving the sampling object optical signal at one of the two optical terminals; a direct-current power supply which applies a predetermined direct-current voltage to the power supply terminal of the electroabsorption optical modulator, the electroabsorption optical modulator exhibiting a high absorption index with respect to the sampling object optical signal at the predetermined direct-current voltage; and a photocoupler which receives the sampling optical pulse to input the sampling optical pulse into another of the two optical terminals of the electroabsorption optical modulator, the sampling optical pulse being emitted by the sampling optical pulse generation unit, the photocoupler receiving the sampling object optical signal to output the sampling object optical signal as the optical pulse signal, the sampling object optical signal being emitted by the other of the two optical terminals of the electroabsorption optical modulator, and wherein when the sampling optical pulse is input, the absorption index is lowered by a mutual absorption saturation characteristic of the electroabsorption optical modulator, and the sampling object optical signal is passed onto a side of the other of the two optical terminals of the electroabsorption optical modulator to perform the synchronization sampling.