Energy-time entangled two-photon generating method

Abstract

The invention belongs to the technical field of quantum information science and discloses an energy-time entangled two-photon generating method. The method includes: step one, emitting pump light; step two, adjusting the pump light, and sending to second-order nonlinear crystal or crystal waveguide to realize a second-order nonlinear process of cascade optical frequency doubling and spontaneous parametric down conversion in the second-order nonlinear crystal or crystal waveguide to generate energy-time entangled two-photon pairs, wherein adjusting the pump light includes adjusting pump light power and polarization direction and filtering; step three, subjecting light emitted by the second-order nonlinear crystal or crystal waveguide to spectral filtering and wavelength selection, and separating residual pump photons from the energy-time entangled two-photon pairs generated in the step two; step four, separating and extracting signal photons and idler frequency photons from the energy-time entangled two-photon pairs filtered out in the step three. A light source prepared according to the method has advantages of high efficiency, small size, practicality, easiness in integration withoptical fiber systems and the like.

Description

technical field [0001] The invention belongs to the technical field of quantum information science and relates to an energy-time entangled two-photon generation method based on a cascaded second-order nonlinear optical process. Background technique [0002] Energy-time entangled two-photons have a wide range of applications in the field of quantum information science due to their unique quantum properties. Energy-time degrees of freedom entangled photons can support high-dimensional quantum information encoding, such as frequency slices, time slices, etc. Compared with quantum light sources such as polarization entanglement and discrete time slice entanglement, energy-time entangled two photons in the communication band may maintain long-distance and large-capacity stable transmission in complex environments. Using this feature, energy-time entangled double Photon sources are applied to quantum radar, quantum cryptography, quantum teleportation, quantum key distribution, qu...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the shortcomings of the traditional energy-time entangled two-photon generation method, such as low efficiency and high requirements on devices and the environment, the present invention proposes an energy-time entangled two-photon generation method, which can be prepared using mature devices in the communication band Energy-time entangled two-photon source, the method is based on the frequency doubling process and the spontaneous parameter down-conversion process in the cascaded second-order nonlinear crystal or crystal waveguide, and the device using the method of the present invention has the advantages of easy assembly, miniaturization, practicality, and Optical fiber device integration and other characteristics

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