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 proposed for the precise measurement of angles and positions, which have been examined by the use of Al-SiO2-Si PSD. It has been experimentally verified that the PSD is convenient for optical interference to produce 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 added to the PSD measurement system, and that of 20 nm for the position-detection system of a Michelson-type interferometer incorporated with the PSD.