Three-dimensional scanning laser radar based on one-dimensional optical phased array

Abstract

The preset invention discloses a three-dimensional scanning laser radar based on one-dimensional optical phased array, the radar comprises a transmitting end, a coherent receiving end, and a non-coherent receiving end, all of which are one-dimensional arrays. The radar reduces phase control complexity of a three-dimensional scanning phased array and avoids using costly tunable lasers and grating array antennas with large crosstalk. The radar still has significant advantages in speed and integration level of a pure solid state three-dimensional scanning scheme, and has very high practical value.

Description

technical field [0001] The invention belongs to the field of photoelectric detection, in particular to a three-dimensional scanning laser radar based on a one-dimensional optical phased array. Background technique [0002] With the rapid development of autonomous driving technology, solutions based on ADAS (Advanced Driving Assistant System) and robotic cars (Robotic Cars) will usher in a critical period of marketization. Real-time and accurate perception of the environment around the vehicle is not only an application requirement, but also a key factor related to traffic safety and market trust. In the context of sensor fusion, lidar has increasingly become an indispensable core device in autonomous driving with its ultra-high resolution accuracy, active light-emitting detection methods, and mature point cloud modeling methods. By emitting detection light and receiving reflected signal light, lidar can detect targets and measure distances; by detecting and ranging in the e...

AI Technical Summary

Problems solved by technology

In 2018, domestic patent applications for optical phased arrays or laser phased arrays also began to increase gradually. Among them, the patent "a single-wavelength multi-line scanning system based on thermo-optical switches and silicon optical phased arrays" (CN201810240144) proposed Using a thermo-optical switch to output the detection light to sub-arrays with different grating periods, a new architecture for single-wavelength multi-linear scanning is realized. Although this scheme does not require the use of wavelength-tunable lasers, as the number of lines increases, the size of the switch, The number of sub-arrays and the complexity of the control circuit will become serious problems, and even return to O(n 2 ) complexity, which ultimately limits the beam fineness, overall output power, and on-chip insertion loss of optical phased arrays; "Integrated multi-beam optical phased array delay network based on wavelength division Based on the multi-beam optical phased array antenna" (CN201810695911) patent respectively provides the realization scheme of multi-beam optical phased array from two technical paths, but these works mainly focus on how to add photon circuits before the phased array to achieve more complex The problem of the beam control function of the laser radar system was developed, and the design of the optical phased array itself and the composition of the laser radar system were not given in detail; "An optical phased array chip transmitter based on a metal slot The scanning broadband laser phased array system" (CN201810558205) patent uses different optical antennas and decoupling design schemes to reduce the optical antenna spacing to between half and one wavelength, thereby increasing the integration density of antennas on the transmitting side and achieving large-scale Alias-free beam rotation, but the beam fineness of the phased array is inversely proportional to the total size of the phased array. In order to compete with the fine far-field resolution of traditional space optics, the total number of these highly integrated optical antennas will reach Thousands to tens of thousands, greatly increasing the complexity of the control circuit and the burden on the host computer

For a single antenna, process errors will lead to the accumulation of random phase errors and significant losses; for the collocation of these large-size antennas to form a phased array, the finite mode field constraints of the dielectric waveguide will cause adjacent channels when closely juxtaposed. phase crosstalk between them, and then construct a contradictory relationship between the effective scanning range in the direction of the phased array and the effective fineness in the direction of the grating antenna

In addition, such a passive grating antenna array will also occupy a large chip area, increasing the overall cost of the chip system

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