Development of an ultra-micro displacement sensor that consists of the silicon substrate monolithically integrated with several photodiodes in every direction

Abstract

We have developed an ultra-micro displacement sensor (Size:1.3mm X 1.3mm X 1.3mm) that consists of the silicon substrate monolithically integrated with several photodiodes (PD) in every direction and a vertical cavity surface emitting laser (VCSEL). This sensor can measure the liner movement and rotating angle separately. The beam diverged from VCSEL was irradiated to the measured object. PDs receive the reflected light after the reflected light reflected at the measured object. So we can detect the change in the intensity of light reflected by the measured surface, which is based on the liner movement and rotating angle of the measured object. For example, this sensor can measure the liner movement and biaxial tilt and concavo-convex shape for the micro-mirror.