Infrared two-photon coincidence measurement device and method based on periodically poled lithium niobate waveguide

Abstract

The invention discloses an infrared two-photon coincidence measurement device and method based on a periodically poled lithium niobate waveguide, and the device comprises an infrared laser device, the laser emitted by the infrared laser device sequentially passes through an optical fiber attenuator and a polarizer and then enters an optical fiber beam splitter, and the incident light is divided into two light beams; one beam of light is received by a single-photon detector after being subjected to two-photon up-conversion through a PPLN waveguide to generate visible light; and the other beam of light is received by a light intensity detector for calculating the light intensity entering the PPLN waveguide, and the infrared two-photon up-conversion efficiency of the corresponding two-photon coincidence measurement device is obtained by comparing the counting rate of the single-photon detector with the detection dependency relationship of the light intensity detector. The infrared two-photon coincidence detector overcomes the defects that an existing infrared single-photon detector is low in efficiency and large in noise, infrared two-photon coincidence measurement can be achieved more efficiently, and second-order interference experiments and application research of infrared photons are facilitated.

Description

technical field [0001] The invention belongs to the technical field of quantum optics, and in particular relates to an infrared two-photon coincidence measuring device and method based on a periodic poled lithium niobate waveguide. Background technique [0002] The earliest application of coincidence measurement appeared in physics, where the purpose was to determine whether multiple events occurring simultaneously or within a very short period of time were related. Events that do have correlation are generally called true coincidence, which is to distinguish them from accidental coincidence events. From a statistical point of view, correlation does not necessarily mean that there is a causal relationship. In terms of quantum mechanics, coincidence measurement is first widely used in the detection and judgment of entangled photon pairs, and it is also used in fields such as single-photon interference. Now there are a variety of relatively mature technologies to achieve coin...

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Problems solved by technology

[0007] The technical problem to be solved by the present invention is to provide an infrared two-photon coincidence measurement device and method based on a periodically poled lithium niobate waveguide for the deficiencies in the above-mentioned prior art. The method of converting photon pairs into visible light single photons, and then using high-performance visible light detectors to detect optical signals, realizes more accurate and efficient infrared two-photon coincidence measurement, and solves the problem of infrared single-photon detection in the current infrared two-photon detection system The problem of low efficiency and high noise of the detector and the problem that the infrared two-photon coincidence measurement system based on two-photon absorption cannot work under low-light conditions

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