Electrooptic modulator of periodically poled lithium niobate based on defect structure

Abstract

The invention discloses a method for setting an electrooptic modulator for enabling an incident light wave polarization direction to rotate on the basis of an electrooptic effect. The method is characterized by comprising the step of introducing a defect structure in a lithium niobate crystal with a periodic structure. The defect structure is positioned at the middle of the crystal and has the width which is 2 times of the normal thickness. When a fundamental wave enters the crystal, the polarization direction gradually rotates, and rotates along the reverse direction after passing through a defect position; an emergence light wave exits in a form of keeping a polarization state same as the original light wave polarization direction and has a phase generating large change. The invention has the advantages of novel arrangement and feasible preparation, and can have a wide application prospect in the field of photo-communication.

Description

technical field [0001] The invention relates to the field of optoelectronic technology, in particular to the electro-optic interaction in a periodically poled lithium niobate (PPLN) superlattice containing a defect structure, and a novel electro-optic modulator arrangement based on the effect. More specifically, it is an electro-optic modulator that changes the polarization state of incident light through the electro-optic effect and then changes the phase of the light wave. Background technique [0002] At the end of the last century, the global information industry developed rapidly, and people's demand for communication is also increasing. People not only require more and more voice, data, image and other services to be transmitted, but also hope to be able to communicate at a faster speed and higher The quality, more convenient way to obtain information. In this situation, pressure and momentum are put on the information transmission system. High-speed, high-efficiency...

AI Technical Summary

Problems solved by technology

However, due to the relatively large dielectric constant of lithium niobate crystals, the speed mismatch between microwaves and light waves is relatively large, and the modulation bandwidth is limited. To increase the bandwidth of the device, complex settings for waveguides and electrodes are required.

Moreover, the volume of interferometric and phase modulation devices is relatively large, so their integration is limited.

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