Frequency chip entangled two-photon source

Abstract

The invention relates to a frequency-bin entangled two-photon source, and belongs to the technical field of quantum information science. According to the frequency chip entangled two-photon source, on the basis of an improved Sagnac ring structure, correlated photon pairs are generated through a second harmonic generation process and a spontaneous parametric down-conversion process which are cascaded in a cross-polarization laser bidirectional pumping optical fiber coupling second-order nonlinear crystal waveguide; and frequency chip entangled photon pairs are generated through polarization control, quantum interference and polarization beam splitting. Two photons obtained through the structure have the advantages of being high in brightness and purity, miniaturization and integration of the frequency chip entangled two-photon source structure can be achieved, existing mature optical fiber communication devices can be adopted as the devices used in the frequency chip entangled two-photon source structure, and high practicability is achieved.

Description

technical field [0001] The invention belongs to the field of quantum information science and technology, and particularly relates to a frequency slice entangled two-photon source. Background technique [0002] Frequency slice entangled photon pairs are an important resource in quantum information technology and have potential applications in quantum precision measurement, quantum cryptography, quantum communication in noisy channels, and delocalized dispersion cancellation in quantum interferometers. . [0003] The generation of frequency-plate entangled photon pairs usually requires nonlinear optical processes in nonlinear optical media, and common processes include second-order nonlinear optical processes and third-order nonlinear optical processes. For example, the spontaneous parametric down-conversion process in nonlinear crystals such as periodically polarized lithium niobate crystal (PPLN) and periodically polarized potassium titanate phosphate crystal (PPKTP), and t...

AI Technical Summary

Problems solved by technology

[0004] The current method of generating frequency sheet entangled photon pairs through bulk second-order nonlinear crystals usually needs to be realized through a spatial optical path, which cannot meet the needs of system miniaturization and integration; and the third-order nonlinearity through spontaneous four-wave mixing process The process produces entangled photon pairs relatively inefficiently, resulting in a low rate of entangled photon pairs

At the same time, in the scheme of using the spontaneous four-wave mixing effect to generate frequency plate entangled photon pairs, the method of injecting energy-time entangled photon pairs into the non-equilibrium Mach-Zehnder interferometer is a main technical route. The pure output of this method is The associated photon pairs are in a mixed state, the purity of the frequency sheet entanglement is low, and time domain filtering is required in the application process

Images