Method and device for improving work efficiency and bandwidth of lithium niobate high-speed optical modulator

Abstract

The invention disclose a lithium niobate high-speed optical modulator, comprising an optical waveguide and a traveling wave electrode, wherein the middle parts of the optical waveguide and the traveling wave electrode form into an interaction region with a coplanar waveguide structure; two ends of the traveling wave electrode outside the range of the interaction region are respectively formed to be an input region and an output region. The lithium niobate high-speed optical modulator is innovated in that the length of the traveling wave electrode between the interaction region and the output region is prolonged so as to form an electric reflection inhibiting region between the interaction region and the output region, and the structure parameter of the traveling wave electrode in the range of the electric reflection inhibiting region is the same with that of the traveling wave electrode in the range of the interaction region. The lithium niobate high-speed optical modulator has the advantages that, the negative effect of the electric reflection microwave signal can be effectively inhibited, the work efficiency and bandwidth of the lithium niobate high-speed optical modulator are improved, and the device performance is enhanced.

Description

technical field [0001] The invention relates to a high-speed optical modulator, in particular to a method and a device for improving the working frequency and bandwidth of the lithium niobate high-speed optical modulator. Background technique [0002] At present, lithium niobate high-speed optical modulators (also called lithium niobate electro-optical modulators) are a more commonly used optical modulation device in the engineering field. The current mainstream technology generally adopts a coplanar waveguide structure (CPW, also called a coplanar waveguide Traveling wave electrode structure) to make lithium niobate high-speed optical modulator, the principle is as follows figure 1 shown; based on the existing theory, when the terminal load and the characteristic impedance of the traveling wave electrode are different (that is, the impedance mismatch), the electric reflection microwave signal (noise) will be excited at the end of the traveling wave electrode (output are...

AI Technical Summary

Problems solved by technology

[0002] At present, lithium niobate high-speed optical modulator (also called lithium niobate electro-optical modulator) is a commonly used optical modulation device in the engineering field. The current mainstream technology generally adopts coplanar waveguide structure (CPW, also called coplanar waveguide) Traveling wave electrode structure) to make lithium niobate high-speed optical modulator, the principle is as follows figure 1 shown; based on the existing theory, when the terminal load and the characteristic impedance of the traveling wave electrode are different (that is, the impedance mismatch), the electric reflection microwave signal (noise) will be excited at the end of the traveling wave electrode (output area), and the electric reflection microwave signal (noise) will be excited. The reflected microwave signal will be reversely transmitted to the input area and form a resonance with the RF input signal, which will lead to a decrease in the operating frequency and bandwidth of the lithium niobate high-speed optical modulator. Therefore, in theory, the terminal load and the traveling wave electrode should be The characteristic impedance is exactly the same; but in the actual process, due to factors such as process tolerance, the characteristic impedance of the terminal load and the traveling wave electrode cannot be completely consistent, resulting in the inevitable existence of the electric reflection microwave signal

Images