Design and Simulation of a Ring-Shaped MEMS Optical Phased Array for 3D Optical Scanning

MEMS constitutes a promising technological route toward micro-optical devices. This paper presents an innovative electrostatically actuated MEMS optical phased array with a concentric-ring structure, specifically designed for 3D optical scanning. Based on the ring-shaped MEMS optical phased array, a novel 3D optical scanning method utilizing the expansion of focused ring is proposed and studied. A detailed elucidation of the implementation mechanism and physical limits of the 3D scanning method is clarified through the mathematical modeling of the annular reflectivity function. The ring-shaped MEMS optical phased array is optimized using the angular spectrum diffraction method in conjunction with COMSOL finite-element simulations. The optimized device achieves focused spot lateral and axial dimensions of 1.282 and 1.664 times the diffraction limit, respectively, with an axial scanning range from 615.4 mm to infinity and a lateral scanning range of 0–6.5 mrad. The driving voltage of the array elements is below 21 V, and their response speed is on the order of microseconds. These findings suggest that the ring-shaped MEMS optical phased array is promising for 3D scanning.