Research on a Miniature Optical Force Accelerometer

Abstract

The accelerometer is one of the vital core components in inertial navigation and guidance systems, which can greatly affect the performance of the whole system. With the development of optical levitation technology recently, the optical force accelerometer based on the latest principle is gradually developing and improving. However, limited by the large volume of the whole system, almost the optical force accelerometers reported cannot be used in a variety of miniature inertial and mechanical sensors. Hence, a miniature optical force levitation system is proposed to reduce the size as much as possible. The optical force levitation system includes one particle cavity fabricated by Micro-Electro-Mechanical System(MEMS) process and an optical system consists of one laser diode and a pair of lenses. The volume of the system is Φ 10 mm × 33 mm. Then the optical force accelerometer including the optical force levitation system and the fourQuadrant Photoelectric Detector (QPD) is built up. The volume of the system is 200 mm × 100 mm × 100 mm. By using one SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> whose diameter is 10 μm trapped by the optical trap in the air as the sensing unit, the stability of this accelerometer is tested and evaluated at last. The result shows that the bias stability of the accelerometer in an hour is 3.2 mg. Based on these consequences, this optical force accelerometer can be a new style of acceleration system which may be used in the navigation system and other sensing fields in the future.