Silicon-based electro-optical modulator

Abstract

The invention discloses a silicon-based electro-optical modulator. The silicon-based electro-optical modulator comprises a substrate layer, an insulating layer and an optical waveguide layer which arestacked in sequence, a traveling wave electrode arranged above the optical waveguide layer and a metal gate-shaped structure periodically arranged in the electric signal transmission direction of thetraveling wave electrode, wherein the metal gate-shaped structure is arranged above the optical waveguide layer, and the group velocity of the electric signal transmitted on the traveling wave electrode with the metal gate-shaped structure at the periphery is matched with the group velocity of an optical carrier transmitted in the optical waveguide of the optical waveguide layer. The metal gate-shaped structure is added around the traveling wave electrode, on the one hand, the electromagnetic wave group velocity of the traveling wave electrode is matched with the group velocity of an opticalcarrier to improve the electro-optical matching degree of the traveling wave electrode, and on the other hand, the traveling wave electrode is shielded from radiating an electromagnetic field into thelow-resistance silicon substrate to reduce the microwave loss of the traveling wave electrode, and the electro-optical bandwidth of the electro-optical modulator is effectively improved.

Description

technical field [0001] The present application relates to the technical field of optical communication, in particular to a silicon-based electro-optical modulator. Background technique [0002] In silicon-based integrated optoelectronic systems, traveling wave electrode modulators are widely used due to their high extinction ratio and easy integration. They are generally based on SOI (silicon-on-insulator, silicon-on-insulator) technology. into a silicon-based electro-optic modulator. A traveling-wave electrode modulator based on SOI technology is generally composed of an optical waveguide load and a traveling-wave electrode. The electromagnetic wave is transmitted between the traveling-wave electrodes, and the optical carrier is transmitted in the load optical waveguide. In the process of optical carrier and electromagnetic wave transmission, the interaction between the electromagnetic wave and the optical carrier causes the phase of the optical carrier to change, thereby ...

AI Technical Summary

Problems solved by technology

Since the substrate silicon used in some processes is low-resistance silicon, and the resistivity of the low-resistance silicon substrate is low, the electromagnetic field radiated from the traveling-wave electrode to the low-resistance silicon substrate will be seriously attenuated, resulting in modulation of the traveling-wave electrode. The device has a high microwave loss, so that the overall electro-optic bandwidth of the traveling wave electrode modulator is relatively low, which seriously limits the performance and application of the traveling wave electrode modulator

Moreover, in the design of traveling-wave electrode modulators, generally because the group velocity of the electromagnetic wave is greater than that of the optical carrier, there will be a speed mismatch between the electromagnetic wave and the optical carrier during transmission, which will further reduce the electro-optical bandwidth of the modulator.

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