Pb₂CrO₅薄膜高速高分解能光位置センサ

抄録

A high resolution of less than 2 nm and high speed response of 25 kHz is realized by an optical beam position sensor with a gold-diffused Pb₂CrO₅ thin film layer. A Pb₂CrO₅ film layer is prepared using an electron beam evaporation deposition technique. Incorporation of thermal diffusion treatment of an evaporated Au layer into the Pb₂CrO₅ film increases drastically the photosensitivity, without degrading the spectral photoresponse characteristics and ratio of photocurrent and dark current. The photo-sensing device has three parallel planar gold electrodes evaporated on tie film surface in a configuration with two narrow electrode gaps. The photocurrent obtained from the central electrode depends lineally upon the light beam position. The device has excellent characteristics of the position sensitivity of 240mV/μm and the linearity deviation of ±1% in the effective measuring range of 40μm. Observation of the surface displacement of a piezoelectric multi-layer actuator is demonstrated by using the photo-sensing device.