A non-degenerate polarized entangled source system using periodically polarized lithium niobate thin film waveguide and its working method

A periodically polarized, thin-film waveguide technology, applied in the field of quantum information, can solve the problems of large device size, unfavorable large-scale popularization, high instrument cost, etc., and achieves the effect of compact device structure, saving research funds, and small device volume.

Active Publication Date: 2020-06-09
SHANDONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although the generation efficiency of entangled photon pairs has been significantly improved, since the nonlinear crystals used in the above-mentioned polarized entanglement sources are all bulk materials, the entire entanglement source device is relatively large, which is not conducive to the compact design of the device.
Moreover, the polarization entanglement source of the Mach-Zehnder interferometer structure needs to use two periodically polarized second-order nonlinear crystals, and the cost of the required equipment is relatively expensive, which is not conducive to large-scale popularization.
Moreover, when the degenerate entangled photon source is used as a single photon source, if both photon wavelengths are in the communication band, the commonly used silicon-based avalanche diode detector cannot be used to detect heraled photons

Method used

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  • A non-degenerate polarized entangled source system using periodically polarized lithium niobate thin film waveguide and its working method
  • A non-degenerate polarized entangled source system using periodically polarized lithium niobate thin film waveguide and its working method
  • A non-degenerate polarized entangled source system using periodically polarized lithium niobate thin film waveguide and its working method

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Embodiment 1

[0057] A nondegenerate polarization entanglement source system utilizing periodically poled lithium niobate thin-film waveguides, such as figure 1 As shown, it includes a laser 1, a first half-wave plate 2, a dichroic mirror 3, a first detector 4, a second detector 5, a polarization beam splitter 6, a second half-wave plate 7, and a first mirror 8. The second mirror 9, the periodically poled lithium niobate waveguide 10;

[0058] The laser 1, the first half-wave plate 2, the dichroic mirror 3, the polarizing beam splitter 6, the second half-wave plate 7, and the second mirror 9 are sequentially arranged along the optical path; the dichroic mirror 3 is connected to the first detector 4; the polarization beam splitter 6 is connected to the second detector 5; the polarization beam splitter 6, the second half-wave plate 7, the second reflection mirror 9, the periodically poled lithium niobate waveguide 10, and the first reflection mirror 8 in sequence end-to-end connection;

[0...

Embodiment 2

[0070] A non-degenerate polarization entanglement source system using periodically poled lithium niobate film waveguide, the difference is:

[0071] In step A, a lithium niobate film 12 with a thickness of 400 nm is grown on a silicon dioxide layer 13 with a thickness of 20 μm; in the step B, a lithium niobate film 12 is deposited on the surface of the lithium niobate film 12 by magnetron sputtering Chromium layer 11 with a layer thickness of 600 nm.

[0072] In step F, the sample is placed on a piezoelectric platform with an XY axis with a precision of 7nm, and the objective lens is placed on a piezoelectric platform with a z-axis with a precision of 100nm, the numerical aperture of the objective lens is NA=0.7, and the magnification of the objective lens is 100 times. The objective produces a laser spot of 800nm-2μm. The light spot emitted from the laser 1 is about 200 microns, passes through a lens with a focal length of 4 mm, and then passes through an objective lens with...

Embodiment 3

[0076] A non-degenerate polarization entanglement source system using periodically poled lithium niobate film waveguide, the difference is that in step F, a 1 μm laser spot is generated by using the objective lens.

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Abstract

The invention relates to a non-degenerate polarization-entangled source system utilizing a periodically polarized lithium niobate thin film waveguide, and an operating method thereof. The non-degenerate polarization-entangled source system comprises a laser, a first half-wave plate, a dichroic mirror, a first detector, a second detector, a polarization beam splitter, a second half-wave plate, a first reflector, a second reflector and the periodically polarized lithium niobate thin film waveguide. The required entangled source structure can be obtained by using just one piece of periodically polarized crystal, laser is split into two possible paths by means of the polarization beam splitter, then the two possible paths of laser pass through the periodically polarized optical waveguide fromopposite directions, pump light generates an entangled phonton pair in each of the two paths. The non-degenerate polarization-entangled source system is compact in device structure, and optical components used in the interferometer portion can be manufactured in an integrated optical path, thereby laying a foundation for integration and scale production of the entangled source.

Description

technical field [0001] The invention relates to a non-degenerate polarization entanglement source system using a periodically poled lithium niobate film waveguide and a working method thereof, belonging to the technical field of quantum information. Background technique [0002] In quantum mechanics, when several particles interact with each other, because the properties of each particle have been integrated into the overall property, the properties of each particle cannot be described separately, but the properties of the overall system can only be described. This phenomenon is called quantum entanglement . [0003] An important component in many research programs for quantum technologies is a high-quality source of single photons or entangled photon pairs. At present, the more entanglement sources used in experiments are the polarization entanglement sources that use type-II BBO crystals to generate down-converted light. The corresponding phase matching angles are calcula...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G02F1/35G02F1/355G02F1/365
CPCG02F1/3501G02F1/3558G02F1/365G02F1/3503
Inventor 逯鹤陈思齐
Owner SHANDONG UNIV
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