On-chip periodic variation refractive index lens photon chip three-dimensional coupler and preparation method thereof

Abstract

The invention discloses an on-chip periodic variation refractive index lens photon chip three-dimensional coupler. The coupler comprises a photon chip, a periodic variation refractive index lens layer and an optical fiber, wherein the photon chip comprises a silicon substrate, and a ridge waveguide, an analogue-spot converter and a grating which grow and are etched on the top surface of the silicon substrate; an input port of the analogue-spot converter is equal to the ridge waveguide in width, and is connected with a waveguide port of the ridge waveguide; an output port of the analogue-spot converter is equal to the grating in width, and is connected with an input port of the grating; the periodic variation refractive index lens layer is connected to the top surface of the grating; and the optical fiber is connected to the top surface of the periodic variation refractive index lens layer. The coupler has the advantages of small size, convenience for integration, strong optical field restraint and low demand to the aligning precision, and can achieve efficient and quick coupling between the chip and the optical fiber. And at the same time, the invention further discloses a preparation method for the coupler; and the preparation method is simple and feasible.

Description

technical field [0001] The invention belongs to the technical field of optoelectronics and integrated optics, and specifically relates to a three-dimensional coupler for a photonic chip with a periodically varying refractive index lens on a chip and a preparation method thereof. The coupler and the preparation method can be used in optical communication systems, optical fiber sensing systems, Optical fiber measurement system, optical computer system and other systems. Background technique [0002] In the development of photonic integration technology, the coupling of waveguide devices and optical fibers has become one of the important technical bottlenecks in its development. First of all, due to the large refractive index of SOI (Silicon-On-Insulator) or InP waveguide, the ability to confine light is strong, and the waveguide can reach submicron or nanometer scale. The mode spot size of the waveguide is smaller than that of the fiber, which causes the mode field mismatch w...

AI Technical Summary

Problems solved by technology

However, the refractive index mismatch involves material problems and is not easy to solve

Due to the large refractive index difference between the fiber-chip material, it is difficult to have a graded-index material that perfectly realizes the refractive index change from 3.5 (SOI or InP) to 1.45 (fused silica) along the longitudinal direction

Moreover, the traditional gradient index lens is a discrete optical element, which is not easy to realize photon integration

Images