Abstract: Embodiments of the disclosure provide a mirror assembly for controlling optical directions in an optical sensing system. The mirror assembly may include a frame and a beam structure mechanically coupled to the frame. The beam structure may define a rotational axis. The mirror assembly may also include a micro mirror suspended by the beam structure. The mirror assembly may further include a plurality of piezoelectric actuators mechanically coupled to the frame and configured to rotate the micro mirror along the rotational axis. Each of the plurality of piezoelectric actuators may be disposed between the rotational axis and an outer edge of the frame.

Abstract: Embodiments of the disclosure provide a mirror assembly for controlling optical directions in an optical sensing system. The mirror assembly may include a substrate and a micro mirror suspended over the substrate by at least one beam. The at least one beam may be mechanically coupled to the substrate. The mirror assembly may also include an actuator configured to tilt the micro mirror with respect to the substrate. The mirror assembly may further include a position sensor configured to detect a position of the micro mirror. Moreover, the mirror assembly may include a bias voltage source electrically coupled to the substrate to bias the substrate with a bias voltage.

Abstract: Embodiments of the disclosure provide systems and methods for detecting a resonant frequency of an optical beam-steering device. The method may include driving the optical beam-steering device with a driving signal oscillating at a plurality of frequencies. The method may also include detecting, by an acoustic detector, an acoustic signal caused by a movement of the optical beam-steering device. The method may further include analyzing a spectrum, by a controller, of the acoustic signal. The method may additionally include determining, by the controller, the resonant frequency of the optical beam-steering device based on the spectrum.

Abstract: Embodiments of the disclosure provide a mirror assembly for controlling optical directions in an optical sensing system. The mirror assembly may include a frame and a beam structure mechanically coupled to the frame. The beam structure may define a rotational axis. The mirror assembly may also include a micro mirror suspended by the beam structure. The mirror assembly may further include a plurality of piezoelectric actuators mechanically coupled to the frame and configured to rotate the micro mirror along the rotational axis. Each of the plurality of piezoelectric actuators may be disposed between the rotational axis and an outer edge of the frame.

Abstract: Embodiments of the disclosure provide methods of bonding silicon wafers. An exemplary method may include cleaning the silicon wafers to remove residues. The method may also include performing a hydrophilic treatment to surfaces of the silicon wafers to increase surface energy. The method may also include pre-bonding the silicon wafers at room temperature. In addition, the method may include performing a rapid thermal annealing treatment to the pre-bonded silicon wafers to bond the silicon wafers.

Abstract: Embodiments of the disclosure provide systems and methods for detecting a resonant frequency of an optical beam-steering device. The method may include driving the optical beam-steering device with a driving signal oscillating at a plurality of frequencies. The method may also include detecting, by an acoustic detector, an acoustic signal caused by a movement of the optical beam-steering device. The method may further include analyzing a spectrum, by a controller, of the acoustic signal. The method may additionally include determining, by the controller, the resonant frequency of the optical beam-steering device based on the spectrum.

Abstract: Embodiments of the disclosure provide a mirror assembly for controlling optical directions in an optical sensing system. The mirror assembly may include a substrate and a micro mirror suspended over the substrate by at least one beam. The at least one beam may be mechanically coupled to the substrate. The mirror assembly may also include an actuator configured to tilt the micro mirror with respect to the substrate. The mirror assembly may further include a position sensor configured to detect a position of the micro mirror. Moreover, the mirror assembly may include a bias voltage source electrically coupled to the substrate to bias the substrate with a bias voltage.