Optical accelerometer based on high-order diffraction beam interference

摘要

We design and fabricate a novel optical accelerometer based on high-order diffraction beam interference with a built-in phase-generated carrier modulator. A proof-of-concept prototype is tested and achieves a resolution of 96 ng/(Hz)~(1/2) with a dynamic range of 60g. By employing optical interference between +-1 order diffraction beams from a grating translating perpendicular to an optical beam for acceleration sensing, the accelerometer realizes a wide dynamic range, while maintaining a high resolution. Compared with prior optical accelerometers, the interference in this structure is free from the effect of short coherence length or beam divergence, and a greater than ordinary dynamic range is obtained. The proposed design is also applicable to a MOEMS platform, offering a new thought in the design of high-performance MOEMS accelerometers.