Electrooptical modulator

Abstract

The invention provides an electrooptical modulator which comprises a base, a Y-type optical waveguide formed on the substrate, a pair of first electrodes arranged on the base and a pair of second electrodes arranged on the substrate. The Y-type optical waveguide comprises a first branch and a second branch, the first branch comprises a first sub-Y-type optical waveguide, the first sub-Y-type optical waveguide comprises a first sub-branch and a second sub-branch, the second branch comprises a second sub-Y-type optical waveguide, and the second sub-Y-type optical waveguide comprises a third sub-branch and a fourth sub-branch. The pair of the first electrodes and the pair of the second electrodes are used for modulating the first sub-Y-type optical waveguide and the second sub-Y-type optical waveguide respectively to enable the light beam output by the first sub-Y-type optical waveguide and the light beam output by the second sub-Y-type optical waveguide to output to be identical in power, and therefore the extinction ratio is increased.

Description

Technical field [0001] The invention relates to a high-speed optical communication system, in particular to an electro-optical modulator. Background technique [0002] The Mach-Zehner electro-optic modulator uses the electro-optic effect to change the equivalent refractive index of one of the two branches of the Y-shaped optical waveguide by modulating the electric field, thereby changing the phase of the light beam propagating in it to make it comparable to the Y-shaped light. The light beam propagating in the other branch of the waveguide has a phase difference. In this way, the light beams transmitted in the two branches of the Y-shaped optical waveguide will interfere after re-convergence, and the output power depends on the phase difference, that is, is determined by the modulating electric field, thereby achieving modulation. However, the power of the light beams transmitted in the two branches of the Y-shaped optical waveguide is often slightly different, resulting in tha...

AI Technical Summary

Problems solved by technology

However, the power of the light beams transmitted in the two branches of the Y-shaped optical waveguide often has a small difference, resulting in that when the electro-optic modulator is used as a switch, there is still a small power output in the off state, but the output power is not the maximum in the on state, and the extinction ratio ( extinction ratio) decreased

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