Large-Aperture kHz Operating Frequency Ti-alloy Based Optical Micro Scanning Mirror for LiDAR Application

Abstract

A micro scanning mirror is an optical device used to scan laser beams which can be used for Light Detection and Ranging (LiDAR) in applications like unmanned driving or Unmanned Aerial Vehicle (UAV). The MEMS scanning mirror’s light-weight and low-power make it a useful device in LiDAR applications. However, the MEMS scanning mirror’s small aperture limits its application because it is too small to deflect faint receiving light. In this paper, we present a Ti-alloy-based electromagnetic micro scanning mirror with very large-aperture (12 mm) and rapid scanning frequency (1.24 kHz). The size of micro-scanner’s mirror plate reached 12 mm, which is much larger than familiar MEMS scanning mirror. The scanner is designed using MEMS design method and fabricated by electro-sparking manufacture method. As the experimental results show, the resonant frequency of the micro scanning mirror is 1240 Hz and the optical scanning angle can reach 26 degrees at resonance frequency when the actuation current is 250 mApp.

Spontaneous Parametric Down-Conversion Induced by Non-Degenerate Three-Wave Mixing in a Scanning MEMS Micro Mirror

“…They are fabricated using integrated circuit and micromachining technologies [5][6][7] . A scanning micro mirror denotes an example of a silicon-based MEMS actuator, often driven at resonance, where one mode of oscillation causes a reflective structure to oscillate and deflect a laser beam [8][9][10][11][12][13][14][15] . For this application, requirements pertaining to the deflection angle that can be reached are of great importance.…”

Investigation of Electromagnetic Angle Sensor Integrated in FR4-Based Scanning Micromirror

“…Scanning micromirrors are essential core elements in various optical microsystems (e.g., barcode reader, endoscopic probe, and LiDAR) [1][2][3][4]. Especially, a large-aperture and low-frequency micromirror is required for a broad range of applications, such as fluorescence microscopes [5], laser projection [6,7], micro-spectrometers [8][9][10], etc.…”

Editorial for the Special Issue on MEMS Mirrors

“…There are 15 papers published in this special issue, covering MEMS mirrors based on all of the commonly used actuation mechanisms including electrostatic [1,2,3,4,5], electromagnetic [6,7,8], piezoelectric [9], and electrothermal [10,11,12,13,14]. Half of these papers explore various aspects of MEMS mirrors, such as working in harsh environments [1], spring hardening compensation [3], optimal packaging conditions for resonance operation [5], input saturation control [8], extremely large scan angle [9], overshoot suppression [10], electrothermal actuator modeling [13], and design optimization [14].…”

“…There is also a paper reporting a passive micromirror [15]. The other half of the papers are focused on a range of applications of MEMS mirrors including grayscale photolithography [2], biomedical imaging [4,11,12], laser display [6], and LiDAR [7]. …”

“…Li et al fabricated a two-axis electromagnetic micromirror with Ni electroplated on the mirror plate to eliminate Joule heating and applied the micromirror to a laser display system, effectively reducing laser speckles [6]. Ye et al fabricated a Ti-alloy-based electromagnetic micromirror with a very large aperture of 12 mm and a rapid scanning frequency of 1.24 kHz using electrical discharging and explored its potential application for micro-LiDAR [7]. Lara-Castro et al proposed a vertical scanning electrothermal bimorph micromirror design by employing polysilicon as the heater material [11].…”