Method and device for increasing scanning angle of optical phased array

Abstract

The invention discloses a method and a device for increasing the scanning angle of an optical phased array. The method comprises the following steps: a beam splitting step: splitting an input light beam into two paths of light beams with equal power; a longitudinal direction light beam scanning step: firstly, controlling the two paths of light beams to interfere constructively at an output end, and outputting from one path; then, performing optical path compensation on multiple paths of light beams with equal power to enable the initial phases of the light beams to be the same before diffraction output; and finally, changing the phase difference between adjacent light paths to realize transverse scanning of the emergent light beam at a certain longitudinal angle; a longitudinal reverse light beam scanning step: controlling the two paths of light beams to cancel interference at the same output end, and outputting the two paths of light beams from the other path; and repeating the steps to realize scanning of the emergent light beam in the longitudinal reverse direction. By means of the method and system, two-dimensional large-angle scanning can be achieved, and the longitudinal scanning angle is doubled; meanwhile, a device control system is simple, small in size, easy for system-on-chip integration and suitable for large-scale production and application.

Description

technical field [0001] The invention belongs to the field of optical phased array and laser radar, and more specifically relates to a method and device for improving the scanning angle of optical phased array. Background technique [0002] The rise of intelligent systems such as self-driving cars and intelligent robots has drawn attention to lidar systems. For lidar, fast and accurate beam scanning in a large area is a prerequisite for its commercial use. Optical phased array is a kind of light emitting device. By effectively adjusting the antenna, beam scanning can be realized. This device has a wide range of applications in lidar, and can also be used in optical imaging and military defense fields . [0003] Optical phased array devices based on waveguide technology have smaller size, lower power consumption and faster scanning speed, making them attract much attention in the fields of lidar, free space optical communication, and optical imaging and display. However, th...

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Problems solved by technology

However, the scanning of the laser radar beam mainly depends on the diffraction output of the grating in the array antenna. The diffraction angle is mainly affected by the inherent parameters of the grating, and the scanning range is limited; The integration of the antenna is low; at the same time, the phase difference between the adjacent waveguides of the array antenna needs to be controlled during the scanning process, and the system is complex

In the existing technology, multiple two-dimensional optical phased arrays or antenna array units are mainly used to expand the scanning range and achieve full coverage of the scanning area, which not only increases the volume of the device, but also increases the complexity of the control system and running costs, but also slows down beam scanning

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