A Mode Converter Based on Asymmetric Bragg Grating

Abstract

The invention discloses a mode converter based on an asymmetrical Bragg waveguide grating. The mode converter comprises a symmetrical Y-fork waveguide, a section of single-mode input waveguide, a section of asymmetrical Bragg waveguide grating and a section of single-mode output waveguide, wherein the Bragg waveguide grating is designed on one side edge of a ridge waveguide, a TE (transverse electric) mode and a TM (transverse magnetic) mode in the waveguide are coupled under the periodic perturbation action of the refractive index of the Bragg waveguide grating, and the mode converter realizes conversion between the TE mode and the TM mode and has the characteristics of simple design structure, large bandwidth, compactness, large production tolerance and the like; the device production technology has CMOS (complementary metal-oxide-semiconductor) technology compatibility, so that the device is easy to integrate and extend, low-cost production is facilitated, and the device can be widely applied to on-chip high-density-integrated high-speed optical communication systems.

Description

technical field [0001] The invention relates to an optical mode conversion integrated device, in particular to a mode converter based on an asymmetric Bragg grating. Background technique [0002] With the continuous development of today's society, people's demand for network data volume is constantly increasing, and the requirement for improving the speed of communication network is becoming more and more urgent. At present, the optical communication network is shouldering this historical mission and moving towards the goal of low cost, large capacity and high speed. Now the optical transport network of 40Gb / s has been widely used, and the optical network of 100Gb / s is in the vigorous development stage. A consensus has been reached on the adoption of a standardized codec method in an optical network with a speed exceeding 100Gb / s. This codec method is based on the coherent reception dual-polarization quadrature phase-shift keying modulation technique (PM-QPSK). In PM-QPSK,...

AI Technical Summary

Problems solved by technology

The mode converters currently proposed are mainly based on three structures: the first one is the L-shaped waveguide structure, which can realize the mutual conversion of the two modes, but its disadvantage is that there is a strict beat length, and the length of the device needs to be adjusted. Careful control; the second is based on the directional coupler structure, which can only realize the conversion of a single mode, such as from TE mode to TM mode, or TM mode to TE mode, and there are also strict coupling lengths and process tolerances small; the third is a structure based on a graded waveguide, which can realize the mutual conversion of modes, but the height of the waveguide changes abruptly, which is not conducive to the input or output of light

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