PRECISE ANGLE AND POSITION DETECTION UTILIZING OPTICAL INTERFERENCE ON METAL-OXIDE-SEMICONDUCTOR-TYPE POSITION-SENSITIVE DETECTORS

The optical interference effect is applied to the previously presented metal-oxide-semiconductor (MOS)-type position-sensitive detector (PSD ) to achieve more precise measurements. New interference methods are p roposed for the precise measurement of angles and positions, which hav e been examined by the use of Al-SiO2-Si PSD. It has been experimental ly verified that the PSD is convenient for optical interference to pro duce periodic output signals indicating half-wavelength displacement. A resolution of one second has been demonstrated for the simple angle- detection system in which only an optical-parallel glass plate is adde d to the PSD measurement system, and that of 20 nm for the position-de tection system of a Michelson-type interferometer incorporated with th e PSD.