CN-224232087-U - Isotactic photon pair light source

CN224232087UCN 224232087 UCN224232087 UCN 224232087UCN-224232087-U

Abstract

The application provides an isotactic photon pair light source, which comprises a pump laser, a nonlinear waveguide, a filter, a wavelength division multiplexer and a single photon frequency shifter, wherein a plurality of isotactic photon pairs with different wavelengths can be output through the single nonlinear waveguide, the structure is simple and compact, the integration level is high, the spectrum range of the produced isotactic photon pairs is wider, and a plurality of wave bands and various application scenes such as a quantum communication wave band, a quantum measurement wave band, a quantum optical experiment wave band and the like are supported.

Inventors

ZHAO YUANYANG
Ge Yude
ZHOU XINGJIN
ZHANG MIN
GONG PAN

Assignees

合肥硅臻芯片技术有限公司

Dates

Publication Date: 20260512
Application Date: 20250624

Claims (10)

1. An isotactic photon pair light source comprising: a laser light source for generating a continuous or pulsed laser light of a specific wavelength, The nonlinear waveguide is connected with the output end of the laser light source and is used for receiving laser emitted by the laser light source, generating nonlinear optical processes and generating n pairs of entangled photon pairs with different wavelengths, wherein each entangled photon pair comprises a signal photon and an idler photon, and the polarization directions of the signal photon and the idler photon are the same; The filter is connected to the output end of the nonlinear waveguide and is used for filtering out laser which is output by the nonlinear waveguide and does not generate a nonlinear optical process; The wavelength division multiplexer is connected with the output end of the filter and is used for separating the generated signal photons in the n pairs of entangled photon pairs from idler photons, outputting the signal photons from n photon ports to n photon output paths respectively, outputting the signal photons from the 1 st to n/2 nd photon ports and outputting the idler photons from the (n/2+1) th to n th photon ports; The n/2 single-photon frequency shifters are arranged on photon output paths corresponding to the 1 st to n/2 nd photon ports or on photon output paths corresponding to the (n/2+1) th to n th photon ports, and are used for performing frequency shifting operation on all signal photons so that the frequencies of the signal photons are consistent with the corresponding idler frequency photons or performing frequency shifting operation on all the idler frequency photons so that the frequencies of the idler frequency photons are consistent with the corresponding signal photons, so that identical photon pairs with n pairs of polarization directions and the same photon frequencies are obtained.
2. The isotactic photon pair light source of claim 1, wherein a first polarization controller is further arranged between the laser light source and the nonlinear waveguide, the first polarization controller being used for precisely adjusting the polarization state of the laser light emitted by the laser light source so as to maximize the nonlinear optical process intensity in the nonlinear waveguide.
3. The isotactic photon pair light source of claim 1 wherein the nonlinear waveguide is a lithium niobate periodically polarized waveguide producing entangled photon pairs by undergoing a type 0 or type I spontaneous parametric down-conversion process.
4. The isotactic photon pair light source of claim 1 wherein the nonlinear waveguide is a silicon nanowire waveguide, and entangled photon pairs are generated by the occurrence of a spontaneous four-wave mixing process.
5. The isotactic photon pair light source of claim 1 wherein a second polarization controller is disposed on at least one of the photon output paths for compensating for polarization changes in the transmission path that occur with entangled photon pairs.
6. The isotactic photon pair light source of claim 1 wherein an optical delay is provided on at least one photon output path for compensating for a time difference due to a transmission path difference of the signal photons and the idler photons.
7. The isotactic photon pair light source of claim 3 wherein the first polarization controller is an electro-optic polarization controller, the filter is an on-chip filter, the wavelength division multiplexer is an on-chip wavelength division multiplexer, and the first polarization controller, the nonlinear waveguide, the filter, and the wavelength division multiplexer are integrated into the same chip.
8. The isotactic photon pair light source of claim 1, wherein the single photon frequency shifter comprises an acousto-optic modulator, the wavelength division multiplexer being connected to the acousto-optic modulator by an optical fiber.
9. The isotactic photon pair light source of claim 1 wherein the single photon frequency shifter comprises an electro-optic modulator, the wavelength division multiplexer being connected to the acousto-optic modulator by an optical fiber.
10. The isotactic photon pair light source of claim 7, wherein the single photon frequency shifter comprises a lithium niobate waveguide, and the first polarization controller, the nonlinear waveguide, the filter, the wavelength division multiplexer, and the single photon frequency shifter are integrated into the same lithium niobate optical chip.

Description

Isotactic photon pair light source Technical Field The application belongs to the field of quantum information, and particularly relates to a multi-output quantum light source. Background Isotactic photons refer to photons that are identical in all degrees of freedom (e.g., frequency, polarization, path, etc.). Isotactic photons play a vital role in quantum communications and quantum computing. In quantum communication, the indistinguishability of identical photons helps to improve the fidelity of quantum state transmission, thereby ensuring the safety of communication. In addition, when the quantum network is constructed by isotactic photons, the quantum entanglement distribution and exchange can be effectively realized, and the possibility is provided for the construction of a multi-node quantum network. In quantum computing, isotactic photons are used to effect manipulation of quantum bits and generation of quantum entanglement. For example, in linear optical quantum computing, the interference effect of isotactic photons is the basis for implementing quantum logic gates. By precisely controlling the interactions of the isotactic photons, complex quantum algorithms, such as glass sampling, can be performed, which helps demonstrate quantum superiority. Current methods of generating isotactic photons include quantum dot emission, parametric down-conversion (SPDC), four-wave mixing (SFWM), and the like. The quantum dot is required to generate isotactic photons by complex micro-nano processing technology, and the environment and excitation conditions of the quantum dot are precisely controlled, so that the requirements on materials, processes and practical operation are high, and the realization is difficult. Parametric down-conversion (SPDC) and four-wave mixing (SFWM) are currently the more common methods for generating isotactic photons, and both are widely used in generating entangled photon pairs, and the technology is mature. However, the photon pairs generated by parametric down-conversion (SPDC) or four-wave mixing (SFWM) have the common problems of low brightness of a light source, narrow spectrum or difficult separation and use of the photon pairs. Disclosure of utility model In view of the above problems and needs, the present application proposes an isotactic photon pair light source capable of outputting a plurality of isotactic photon pairs different in wavelength through a single nonlinear waveguide. The specific scheme is as follows: The application discloses an isotactic photon pair light source, comprising: a laser light source for generating a continuous or pulsed laser light of a specific wavelength, The nonlinear waveguide is connected with the output end of the laser light source and is used for receiving laser emitted by the laser light source, generating nonlinear optical processes and generating n pairs of entangled photon pairs with different wavelengths, wherein each entangled photon pair comprises a signal photon and an idler photon, and the polarization directions of the signal photon and the idler photon are the same; The filter is connected to the output end of the nonlinear waveguide and is used for filtering out laser which is output by the nonlinear waveguide and does not generate a nonlinear optical process; The wavelength division multiplexer is connected with the output end of the filter and is used for separating the generated signal photons in the n pairs of entangled photon pairs from idler photons, outputting the signal photons from n photon ports to n photon output paths respectively, outputting the signal photons from the 1 st to n/2 nd photon ports and outputting the idler photons from the (n/2+1) th to n th photon ports; The n/2 single-photon frequency shifters are arranged on photon output paths corresponding to the 1 st to n/2 nd photon ports or on photon output paths corresponding to the (n/2+1) th to n th photon ports, and are used for performing frequency shifting operation on all signal photons so that the frequencies of the signal photons are consistent with the corresponding idler frequency photons or performing frequency shifting operation on all the idler frequency photons so that the frequencies of the idler frequency photons are consistent with the corresponding signal photons, so that identical photon pairs with n pairs of polarization directions and the same photon frequencies are obtained. Optionally, a first polarization controller is further disposed between the laser light source and the nonlinear waveguide, and the first polarization controller is used for precisely adjusting the polarization state of the laser light emitted by the laser light source, so that the nonlinear optical process intensity of the laser light emitted by the laser light source in the nonlinear waveguide is maximized. Alternatively, the nonlinear waveguide is a lithium niobate periodically poled waveguide that generates entangled photon pairs by undergoing a type 0 or type