Lithium niobate electro-optic phase modulator adopting one forth slide to achieve polarization independent

Abstract

The invention discloses a lithium niobate electro-optic phase modulator adopting one forth slide to achieve polarization independent. The innovation is that the lithium niobate electro-optic phase modulator comprises a lithium niobate chip and the one forth slide; the beneficial technical effects are that the lithium niobate electro-optic phase modulator adopting the one forth slide to achieve thepolarization independent is provided, the structure of the device is simple and ingenious, and the complete polarization independent modulation can be achieved under the condition of not reducing anyindicator.

Description

technical field [0001] The invention relates to a lithium niobate electro-optic phase modulator, in particular to a lithium niobate electro-optic phase modulator which adopts a quarter glass plate to realize polarization-independent. Background technique [0002] In the quantum key distribution system of quantum communication, the phase modulator is generally used for phase encoding; the usual phase modulator is correlated with the polarization direction of light, that is, the modulation efficiency of light with different polarization directions is different, and the polarization-related loss is also Are not the same. Due to the birefringence effect of the optical fiber in the optical path of the system, the polarization direction of the light will inevitably be changed after being transmitted through the optical fiber. Then entering a polarization-related modulator for phase encoding after the polarization direction changes will inevitably cause serious damage to the normal...

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Problems solved by technology

[0005] For polarization-independent electro-optic modulators, there are reports in China that use Z-transfer Ti diffusion LiNbO 3 The waveguide has the same electro-optic coefficient in the X and Y axis directions to achieve fabrication, but at the same time, due to the small electro-optic coefficient of the lithium niobate material in the X and Y axis directions, the fabricated device often requires a higher half-wave voltage. It is difficult to meet the needs of the system

[0006] In recent years, our research group has also integrated the X-cut lithium niobate optical waveguide with the titanium diffusion process and the Z-cut lithium niobate optical waveguide with the titanium diffusion process to achieve polarization independence, but there are still problems such as polarization-dependent loss.

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