To provide a vibration detecting device that optically performs digital vibration detection and allows miniaturization of the device.
A laser beam Lout from a light source 10 is divided into two optical paths (first and second optical paths) and made to proceed by a polarized light beam splitter 130. At this time, an S wave component s1 (reflected light) reflected by a vibrating film 151 via a /4 plate 161 in the first optical path (reflected light path) is made to interfere with a P wave component (reflected light) reflected by a vibrating film 152 via a /4 plate 162 in the second optical path (reference light path) to form an interference pattern. Based on the interference patterns, vibration of the vibrating films 151 is quantized and detected. The vibration of the vibrating films 151 is digitally and optically detected with a constitution more compact than the conventional one.
TANIGUCHI KAYOKO
KURODA AKIHIRO
NOMOTO KAZUTOSHI
Yasushi Santanzaki