US 12,326,521 B2
Lidar system based on silicon-based integrated magneto-optical circulator
Lei Bi, Chengdu (CN); Wei Yan, Chengdu (CN); Shuyuan Liu, Chengdu (CN); Jun Qin, Chengdu (CN); Yan Zhang, Chengdu (CN); and Longjiang Deng, Chengdu (CN)
Assigned to UNIVERSITY OF ELECTRONIC SCIENCE AND TECHNOLOGY OF CHINA, Chengdu (CN)
Filed by University of Electronic Science and Technology of China, Chengdu (CN)
Filed on May 7, 2021, as Appl. No. 17/315,246.
Claims priority of application No. 202010380891.3 (CN), filed on May 8, 2020.
Prior Publication US 2021/0349191 A1, Nov. 11, 2021
Int. Cl. G01S 7/481 (2006.01); G01S 17/88 (2006.01); G02B 6/27 (2006.01); G02B 6/293 (2006.01)
CPC G01S 7/4818 (2013.01) [G01S 7/4812 (2013.01); G01S 17/88 (2013.01); G02B 6/2746 (2013.01); G02B 6/29352 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A lidar system, comprising:
a laser;
an optical detector;
a laser antenna; and
a silicon-based integrated magneto-optical circulator comprising an input port, a receiving port, and an emission port;
wherein:
the silicon-based integrated magneto-optical circulator comprises a silicon-based integrated Mach-Zehnder interference structure or a silicon-based integrated micro-ring structure, and a plurality of silicon-based integrated magneto-optical waveguides;
the laser is aligned and coupled to the input port of the silicon-based integrated magneto-optical circulator via an optical fiber, a grating coupler, or an edge coupler;
the optical detector is aligned and coupled to the receiving port of the silicon-based integrated magneto-optical circulator via the optical fiber, the grating coupler, or the edge coupler;
the laser antenna is aligned and coupled to the emission port of the silicon-based integrated magneto-optical circulator via the optical fiber, the grating coupler, or the edge coupler; the laser is configured to generate a laser light transmitting to the laser antenna via the silicon-based integrated magneto-optical circulator; the laser antenna is configured to collimate the laser light, compress the divergence angle of the laser light, and emits the compressed laser light; moreover, the laser antenna is also configured to receive the reflected light of a detected object;
when the lidar system is used, the input port of the silicon-based integrated magneto-optical circulator is configured to receive a detection signal generated by the laser; the detection signal enters the laser antenna through the silicon-based integrated magneto-optical circulator for single-channel emission, and is reflected by the detected object, thereby generating a reflected signal; the reflected signal is received by the laser antenna, returns to the silicon-based integrated magneto-optical circulator through the emission port, and then returns to the optical detector connected to the receiving port of the silicon-based integrated magneto-optical circulator from another channel, to run in a full-duplex mode; and
the silicon-based integrated Mach-Zehnder interference structure comprises two interference arms, and the plurality of silicon-based integrated magneto-optical waveguides comprise 180° curved waveguides to steer a light to an opposite direction;
a reciprocal phase difference between the two interference arms is an odd multiple of π/2; and a non-reciprocal phase difference between the two interference arms is set to be π/2 by configuring the length of each silicon-based integrated magneto-optical waveguide;
one of the two interference arms is adapted to unidirectionally transmit light in a forward direction, and the other one of the two interference arms is adapted to unidirectionally transmit light in a backward direction; and when in use, the light transmitted in the forward direction and the light transmitted in the backward direction are separated from each other.