Patent ID: 8279438

Claim:
An optical measurement device, comprising: a detected light pulse outputter that receives a predetermined pulse light, and outputs a detected light pulse having a same repetition frequency as a repetition frequency of the predetermined pulse light; a signal outputter that receives the detected light pulse and a sampling light pulse, and outputs a signal corresponding to a power of the detected light pulse upon a reception of the sampling light pulse; a frequency spectrum measurer that measures a magnitude of a signal corresponding to a measured frequency which changes over time; a simultaneous light pulse outputter that outputs a simultaneous light pulse when the predetermined pulse light and the sampling light pulse are simultaneously input; a trigger signal generator that converts the simultaneous light pulse into an electric signal as a trigger signal; and a trigger signal delayer that delays the trigger signal, wherein: the repetition frequency of the detected light pulse and a repetition frequency of the sampling light pulse are different from each other; and the measured frequency starts to change from a time point when the trigger signal is fed to the frequency spectrum measurer.