Micromirror and laser projection system comprising same

Abstract

The invention provides a micromirror and a laser projection system comprising the same. The micromirror comprises a mirror surface, a transition frame, a plurality of flexible springs, a plurality of cantilever beams and a plurality of driving parts, and the plurality of flexible springs, the plurality of cantilever beams and the plurality of driving parts are in one-to-one correspondence; the transition frame is arranged in the periphery of the micromirror, and the micromirror is connected with the transition frame through a plurality of connecting beams; and the multiple flexible springs are arranged at intervals in the circumferential direction of the outer side of the transition frame, one end of each cantilever beam is dynamically connected with the transition frame through the corresponding flexible spring, and the other end of each cantilever beam is connected with the driving part. According to the micromirror, small-amplitude vibration of the movable comb teeth is amplified into large-amplitude vibration of the mirror surface according to the lever amplification principle, the stroke or deflection angle of the micromirror can be improved, the mirror surface is provided with the etching pattern, the wavefront phase of a laser beam is effectively modulated, the technology is simple, the performance is high, and the micromirror is especially suitable for a Fourier transform infrared spectrometer and a projection system for eliminating laser speckles.

Description

technical field [0001] The invention relates to the technical field of microelectromechanical systems in semiconductor technology, in particular to a micromirror. Background technique [0002] Micromirror is an optical device based on semiconductor microprocessing technology. Due to the characteristics of small size, high scanning frequency and low energy consumption, micromirrors have broad application prospects in the fields of lidar, laser scanning projection, endoscope, optical switch and infrared spectrometer. Among them, applications such as lidar have high requirements for the detection field of view, and require a large-angle mechanical deflection of the micromirror. Applications such as infrared spectrometers require the micromirror to vibrate in the vertical direction and require a large stroke. [0003] In order to achieve higher frame rate and resolution, the micromirror must work in high frequency mode. However, excessive dynamic deformation will lead to dist...

AI Technical Summary

Problems solved by technology

At present, there are usually two methods to eliminate laser speckle. The first method uses a wavelength-tunable laser to modulate the distribution of speckle by scanning the laser wavelength in the time domain, but the wavelength adjustment range of the laser is usually limited, which is not enough to completely eliminate it. speckle phenomenon

The second method uses ground glass or an integrator and connects it to a rotary motor, but these devices are bulky, consume a lot of power and are noisy

However, the micromirror usually has only a small vibration amplitude, resulting in a small change in the laser isophase surface, which is not enough to completely uniformize the spot energy

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