Optical antenna, phased array laser radar and preparation method of optical antenna

Abstract

The invention provides an optical antenna, a phased array laser radar and a preparation method of the optical antenna. The optical antenna includes: an SOI substrate, a waveguide structure layer, a spacer layer, a grating structure layer and a protective layer; the SOI substrate includes: a bottom silicon layer, a buried oxide layer and a top silicon layer; a waveguide is formed on the top silicon layer of the SOI substrate The structure layer is provided with a spacer layer, a grating structure layer and a protective layer in sequence above the waveguide structure layer; since the difference between the refractive index of the grating structure layer and the refractive index of the spacer layer and the protective layer is greater than the preset threshold and the grating structure layer The refractive index of the grating structure layer is higher than that of the spacer layer and the protective layer, so the grating structure layer has a high refractive index contrast, so that when the light wave is diffracted in the waveguide structure layer, the diffraction in the direction of the SOI substrate can be eliminated, and the light wave can be successfully launched upwards. Therefore, high radiation efficiency is obtained, and the utilization rate of the optical antenna is greatly improved.

Description

technical field [0001] Embodiments of the present invention relate to the field of radar technology, and in particular to an optical antenna, a phased array laser radar, and a method for preparing the optical antenna. Background technique [0002] The concept of phased array lidar has long been proposed, and various design schemes are constantly being developed. Its basic modules are also mature, such as light source module, beam splitting module, phase modulation module, etc. However, in the optical antenna module, how to efficiently export the phase-modulated light of each waveguide to the photonic integrated circuit is still a huge challenge. This is because the refractive index of the waveguide is much larger than that of air, and it is very difficult to couple light from the waveguide into free space, so that the radiation efficiency of the optical antenna is extremely low, which seriously affects its utilization. [0003] At present, the international optical antennas...

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Problems solved by technology

[0005] The embodiment of the present invention provides an optical antenna, a phased array laser radar and a preparation method of the optical antenna, which solves the problem that the conventional grating is used in the grating optical antenna in the prior art, causing the light coupled from the grating to the waveguide to diverge Serious, the radiation efficiency is extremely low, which leads to the technical problem of extremely low energy utilization rate of the optical antenna

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