| 摘要 |
PROBLEM TO BE SOLVED: To provide a microvibration detecting device capable of restraining influence of 1/F noise, while enhancing energy utilization efficiency of the transmission-reception light. SOLUTION: This device has a light branching coupler for branching a laser beam from a light source, a modulation signal generator for generating a pulse waveform as a modulation signal, a light pulse modulator for modulating the branched laser beam to a light pulse signal, a light amplifier for amplifying the light pulse signal in response to the ratio of a pulse width of the light pulse signal to a pulse repeating period, a transmitting-receiving optical system for receiving the scattered light from a measuring object by irradiating the transmission light, a light circulator for receiving the scattered light corresponding to the transmission light by outputting the amplified light pulse signal to the transmitting-receiving optical system as the transmission light, a light receiver for converting the light into an electric signal by performing heterodyne detection on the branched laser beam and the scattered light, and a signal processor for detecting an oscillation frequency or vibrational displacement of the measuring object by processing the electric signal from the light receiver on the basis of the modulation signal from the modulation signal generator. COPYRIGHT: (C)2006,JPO&NCIPI
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