Integrated Micro Sensor Based on Grating Interferometer: A Review

Sensors based on optical interferometric displacement measurement have the outstanding advantage of high sensitivity and are widely applied in various measurement fields. In particular, with the development of micro-opto-electromechanical system technology, grating-interferometer-based sensors have drawn considerable attention and have been developed rapidly, due to their miniature structure and integrated nature. This article reviews the previous research on the sensing principle, structural integration, and signal demodulation optimization of integrated microsensors based on grating interferometers. To improve the microscale sensing principle, the diffraction characteristics of the micrograting require more accurate analysis, when the critical dimension of the optical path approaches the light wavelength. To achieve a highly integrated system, design, and microfabrication for integrating the microsensitive structures, micrograting and photoelectric modules are gradually being developed. To improve the performance of optical interference sensors, extending their measurement ranges while maintaining high sensitivity and high precision with limited integrated microsystems is becoming a research hotspot. This article concludes by indicating the current challenges and potential future directions in this field.