An electronically controlled polarization entangled state generation chip based on periodically poled lithium niobate waveguide

Abstract

The electronically controlled polarization entangled state generation chip based on periodically polarized lithium niobate waveguide includes a pump beam splitting region, a periodically polarized region, a waveguide optical phase modulator, a waveguide optical path polarization beam splitter, and a dynamic electronically controlled photon delay device. constitute. The pump light beam splitting area is composed of a Y beam splitter and a phase modulator, which realizes the beam splitting and relative phase control of the pump light. The periodically polarized region is composed of periodically inverted ferroelectric domains on two separate waveguides, in which parametric down-conversion photon pairs based on second-order nonlinearity are realized respectively. The waveguide-based optical phase modulator is to make electrodes above the waveguide, and by applying an electric field to change the refractive index of the waveguide to control the phase of photons. The waveguide optical path polarization beam splitter realizes the separation of photons of different polarizations, and realizes the polarization beam splitting operation of the photon pairs generated in the two waveguides. The invention provides a chip-type, stable, high-brightness, high-entanglement, and dynamically switchable polarization entanglement output device.

Description

technical field [0001] The invention relates to the fields of quantum information technology, optoelectronic technology and nonlinear optics, in particular, a chip-based quantum light source is realized by using integrated optical technology and ideas. Background technique [0002] Entanglement is the core resource in quantum information technologies such as quantum communication and quantum computing. Therefore, how to prepare entangled light sources, especially adjustable, efficient, stable, and portable entangled light sources has always been a research difficulty and hot spot in the field of quantum information. The methods for generating entangled photon pairs historically include: (1) atomic cascade transitions [1]; (2) four-wave mixing processes in atomic systems [2]; (3) silicon-based [3,4] or optical fiber The four-wave mixing process of [5,6]; (4) the optical parametric down-conversion process in second-order nonlinear crystals [7,8]. Among them, the atomic casca...

AI Technical Summary

Problems solved by technology

The general polarization entanglement source is realized by the birefringence matching of bulk optical crystals [15], or the coexistence of dual phase matching in periodically polarized crystals [16]. Beamers[17], dichroic mirrors[18] and other optical components are used to assist the implementation, resulting in the optical path of entangled light sources being generally complex, bulky and unstable.

At the same time, the general disadvantage of existing solutions is that one optical path can only output one kind of polarization entanglement, such as one of the polarization entangled states. Bell-based designs have been reported, and quantum information processing often requires different polarization entangled states and fast switching of polarization entangled states

The above requirements prompt people to look for chip-like, dynamically switchable polarization entanglement generation methods, which cannot be realized by traditional implementation schemes.

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