Method for suppressing refraction deviation angle in spontaneous parametric down-conversion process based on single optical wedge

Abstract

The invention relates to a spontaneous parametric down-conversion process refraction deviation angle suppression method based on a single optical wedge, in the spontaneous parametric down-conversion process, in order to suppress the refraction deviation angle after pump light enters a nonlinear crystal, a single optical wedge structure is added in front of the nonlinear crystal, and the method comprises the steps that S1, the wavelengths of entangled light o light and e light are determined to be lambda o and lambda e respectively, determining the wavelength lambda p of the pump light and the material and the size of the nonlinear crystal; determining a crystal cutting angle theta according to a phase matching mode; s2, when the refraction deviation angle of the entangled light in the nonlinear crystal is 0, deducing a relational expression which needs to be met by an incident angle; and S3, determining the refractive index n of the single optical wedge according to the material of the single optical wedge, and calculating the wedge angle alpha c of the single optical wedge in combination with the incident angle relational expression. According to the invention, the influence caused by deflection due to the birefringence effect can be reduced, and the accuracy is high.

Description

technical field [0001] The invention belongs to the technical field of quantum entanglement light sources, and in particular relates to a method for suppressing the deviation angle of refraction in a spontaneous parameter down-conversion process based on a single optical wedge. Background technique [0002] At present, there are many defects in the traditional optical imaging field, such as the resolution is limited by the optical diffraction limit, susceptible to environmental interference, and low precision. The emergence of quantum entanglement imaging technology can effectively solve the above-mentioned traditional imaging problems. In order to realize quantum imaging technology, a two-photon entanglement source with high entanglement and high energy efficiency is the most important part. In recent years, quantum entangled light sources have developed rapidly and have been widely used in quantum detection imaging, quantum computing, quantum key distribution, teleportati...

AI Technical Summary

Problems solved by technology

[0004] In the SPDC process, the collimated pump laser is generally used to be vertically incident on the nonlinear crystal cut into a cuboid traditional structure, but due to the birefringence effect of the nonlinear crystal, the pump light perpendicularly incident on the crystal will have a certain angle deflection, which will affect the satisfaction of the phase matching condition, and then affect the quality of the generated entangled photon pairs. In the specific experimental process, in order to make the generated signal light and idle light propagate on the horizontal plane, it is necessary to adjust the pump light Fine-tuning the direction of propagation, the angle of the wave plate, and the placement direction of the crystal, etc., the adjustment process is complicated and the accuracy is poor

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