Grating device, light emission module and light detection method

Abstract

The application discloses a grating device, a light emitting module and a light detection method. The grating device comprises: a substrate; a barrier layer on the substrate; a first waveguide over a first region of the barrier layer; and a second waveguide over a second region of the barrier layer, Wherein, the grating device selectively propagates the first light beam in the first waveguide and / or propagates the second light beam in the second waveguide, obtains an outgoing light beam with a changed propagation direction through diffraction, and the first light beam and the second light beams are respectively in TE mode and TM mode and have unequal exit angles at at least one wavelength. The grating device uses the wavelength of the source light beam to modulate the exit angle of the exit light beam, and respectively propagates light beams of different polarization modes in the first waveguide and the second waveguide to expand the modulation range of the exit angle. The lidar using the grating device can expand the detection angle.

Description

technical field [0001] The invention belongs to laser radar technology, and more specifically relates to a grating device, a light emitting module and a light detection method. Background technique [0002] LiDAR has been widely used in autonomous driving, optical wireless communication, environmental terrain measurement and other fields. Lidar is similar to microwave radar. It uses emitted beams to irradiate objects, detects reflected light signals of objects, and processes reflected light signals to obtain information such as the position and speed of the detected target. [0003] The work of the laser radar system relies on an expensive optical system. For example, the use of reflectors can change the exit angle of the laser beam, thereby expanding the detection range of the laser radar. In recent years, emerging technologies such as silicon photonics have been used to integrate the basic functions of lidar on a common silicon substrate to form a single chip to reduce th...

AI Technical Summary

Problems solved by technology

[0005] The advantage of using the wavelength modulation method to control the beam emission angle is that only the wavelength of the laser source needs to be controlled without using additional heating elements. The disadvantage is that the range of the emission angle obtained by wavelength modulation is small

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