Light modulator with four-layer graphene structure

Abstract

The invention discloses a light modulator with a four-layer graphene structure and belongs to the field of photoelectronic techniques. The light modulator comprises an SOI light guide, a first ridge part and a second ridge part overlapping the first ridge part are arranged above a semiconductor light guide layer of the SOI light guide, two graphene layers are arranged between the semiconductor light guide layer and the first ridge part, another two graphene layers are arranged between the first ridge part and the second first ridge part, and all the functional layers are isolated from one another through isolation media; one graphene layer between the semiconductor light guide layer and the first ridge part is connected with one graphene layer between the first ridge part and the second first ridge part through one metal electrode, and the other graphene layer between the semiconductor light guide layer and the first ridge part is connected with the other graphene layer between the first ridge part and the second first ridge part through another metal electrode. The light modulator has the advantages of being smaller in size, high in modulation rate and convenient to integrate, wherein the extinction ratio of a 5 micrometer active area is as high as 30 dB, and the modulation rate of a 3 dB modulation bandwidth is as high as 114.8 GHz.

Description

technical field [0001] The invention belongs to the technical field of optoelectronics, and relates to a light modulator, especially a light modulator with a graphene structure. Background technique [0002] The basic structure of the optical modulator includes an optical crystal (or optical waveguide), which is located in the middle of an electric field perpendicular to the direction of light transmission (the electric field can pass through two parallel sides corresponding to the optical crystal or optical waveguide). Add electrodes, and then add a bias voltage between the two electrodes to achieve). Due to the existence of the bias electric field, when the light passes through the optical crystal or the optical waveguide, its refractive index or absorption rate changes, thereby causing a change in the phase or amplitude of the output light, which is the basic working principle of the optical modulator. [0003] The optical modulator plays a vital role in the modulation o...

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Problems solved by technology

[0007] In order to meet the requirements of future optical fiber communication technology, the optical modulator should have higher modulation speed, shorter switching time and realize integration. The existing graphene optical modulator needs to be further improved in terms of volume, modulation rate and switching time.

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