阅读说明：本技术 一种适用于孪生双光束编码的基于纠缠态的量子信息分束装置 (Entanglement state-based quantum information beam splitting device suitable for twin double-beam coding ) 是由 刘楠楠 翟凤潇 刘素娟 郝蕴琦 李萍萍 王东琳 张瑞亮 杨坤 于 2019-11-12 设计创作，主要内容包括：本发明公开了一种适用于孪生双光束编码的基于纠缠态的量子信息分束装置，该装置由第一光学参量放大器、位相调制器、粗波分复用器、纠缠光源、第二光学参量放大器、第三光学参量放大器、第一平衡零拍探测系统、第二平衡零拍探测系统、第三平衡零拍探测系统、第四平衡零拍探测系统、数据采集和运算系统、信息显示系统构成。该装置的特点是孪生双光束编码信息，即利用位相调制器对参量放大器输出的孪生双光束进行调制，实现量子信息编码；一个纠缠光源结合两光学参量放大器实现量子信息分束；分束后量子信息可供四用户同时使用，即此装置的四输出端口的传输系数可同时趋于1。本发明针对孪生双光束编码的量子信息，利用一个纠缠光源结合两参量放大器，可实现四通道无噪声分束。(The invention discloses an entanglement state-based quantum information beam splitting device suitable for twin double-beam coding, which consists of a first optical parametric amplifier, a phase modulator, a coarse wavelength division multiplexer, an entanglement light source, a second optical parametric amplifier, a third optical parametric amplifier, a first balanced homodyne detection system, a second balanced homodyne detection system, a third balanced homodyne detection system, a fourth balanced homodyne detection system, a data acquisition and operation system and an information display system. The device is characterized in that the twin double light beams encode information, namely, the twin double light beams output by the parametric amplifier are modulated by using a phase modulator to realize quantum information encoding; an entangled light source is combined with two optical parametric amplifiers to realize quantum information beam splitting; the beam splitting quantum information can be used by four users at the same time, namely the transmission coefficients of four output ports of the device can tend to 1 at the same time. Aiming at the quantum information of twin double-beam coding, the invention utilizes an entanglement light source to combine with two parametric amplifiers, thereby realizing four-channel noiseless beam splitting.)

1. The utility model provides a quantum information beam splitting device based on entanglement attitude suitable for twin double beam encoding, its characterized in that, the device comprises first optical parametric amplifier (1), phase modulator (2), coarse wavelength division multiplexer (3), entanglement light source (4), second optical parametric amplifier (5), third optical parametric amplifier (6), first balanced homodyne detecting system (7), second balanced homodyne detecting system (8), third balanced homodyne detecting system (9), fourth balanced homodyne detecting system (10), data acquisition and operating system (11), information display system (12), its positional relationship as follows: the first optical parametric amplifier (1) generates a pair of twin beams, the twin beams carry information through phase modulation after passing through a phase modulator (2), the coarse wavelength division multiplexer (3) spatially separates the twin beams carrying the information into two beams, the entanglement light source (4) generates a pair of entangled beams, a first beam of the twin beams and a first beam of the entangled beams are jointly input into a second parametric amplifier (5) to output a first output beam and a second output beam, a second beam of the twin beams and another beam of the entangled beams are jointly input into a third parametric amplifier (6) to output a third output beam and a fourth output beam, the first output beam is input into a first balanced homodyne detection system (7) to output a first output signal, the second output beam is input into a second balanced homodyne detection system (8) to output a second output signal, the third output beam is input into a third balanced homodyne detection system (9) and then outputs a third output signal, the fourth output beam is input into a fourth balanced homodyne detection system (10) and then outputs a fourth output signal, and the first output signal, the second output signal, the third output signal and the fourth output signal are simultaneously input into a data acquisition and operation system (11) for performing the following operations: the first output signal and the fourth output signal are added, the second output signal and the third output signal are added, the third output signal and the first output signal are subtracted, the fourth output signal and the second output signal are subtracted, four paths of signals are output after operation, and the four paths of signals are input into an information display system (12) to analyze the transmission coefficient.

2. An entanglement state-based quantum information splitting device suitable for twin dual beam encoding as claimed in claim 1, wherein the entanglement light source (4) outputs two entangled beams, a first of the entangled beams having the same frequency and spatial mode as a second of the twin beams output from the first parametric amplifier (1), and the other having the same frequency and spatial mode as the first of the twin beams.

3. An entanglement state-based quantum information beam splitting device suitable for twin double-beam encoding as claimed in claim 1, wherein the second parametric amplifier (5) and the third parametric amplifier (6) are the same as the gain medium of the first parametric amplifier (1), and the two adopt the same pump light spectrum and the same parametric gain.

Technical Field

The invention belongs to the field of quantum information processes, and particularly relates to an entanglement state-based quantum information beam splitting device suitable for twin double-beam coding.

Background

The quantum information beam splitter can realize noise-free beam splitting of information, namely the split information has the same signal-to-noise ratio as the original information. When the coherent state is used as an information carrier, the linear beam splitter of the idle port can be filled by using a compressed vacuum state, and the noiseless quantum beam splitting is realized. When quantum state light fields such as a compressed coherent state, a twin light beam and the like are used as carriers, stricter conditions are needed for realizing the noise-free quantum information beam splitting. It has been shown that when information is encoded using one arm of a twin beam, its noiseless splitting can be achieved using an optical parametric amplifier with associated light source injection (see the documents Xueshi Guo, XiaoyingLi, Nannan Liu and z.y. Ou, Quantum information mapping using a fibrous parametric amplifier with a non-configured improved by a fibrous modified input [ J ]. Scientific Reports, 2016, 6(1): 30214).

Recent studies show that information using twin dual beams as carriers has a higher signal-to-noise ratio than information using one of the beams or a compressed coherent state as carriers through post-detection arithmetic processing (see the literature Jiamin Li, yuhongliu, LiangCui, et al. Joint measurement of multiple non-coherent parameters [ J ]. Physical Review a, 2018, 97(5): 052127), i.e. twin dual beams can carry more quantum information. Therefore, the method has important significance in researching the noise-free beam splitting problem of the twin double-beam coded quantum information, and is expected to solve the noise-free beam splitting problem of the twin double-beam coded quantum information through post-operation processing by utilizing the entanglement light source and the optical parametric amplifier, so that the usable quantum information amount is improved, and the number of users is expanded.

Disclosure of Invention

The invention aims to solve the problem of noiseless beam splitting of twin double-beam coded quantum information, and provides an entanglement state-based quantum information beam splitting device suitable for twin double-beam coding.

The solution of the invention is:

the quantum information beam splitting device based on the entangled state is suitable for twin double-beam coding and is characterized in that: the device comprises a first optical parametric amplifier, a phase modulator, a coarse wavelength division multiplexer, a second optical parametric amplifier, a third optical parametric amplifier, a first balanced homodyne detection system, a second balanced homodyne detection system, a third balanced homodyne detection system, a fourth balanced homodyne detection system, a data acquisition and operation system and an information display system. The positional relationship is as follows: the first optical parametric amplifier generates a pair of twin beams which are different in frequency and are transmitted together in space, the twin beams carry information through phase modulation after passing through a phase modulator, the coarse wavelength division multiplexer spatially separates the twin beams carrying the information into two beams, the entanglement light source generates a pair of entangled beams, a first beam of the twin beams and a first beam of the entangled beams are input into a second parametric amplifier together to output a first output beam and a second output beam, a second beam of the twin beams and another beam of the entangled beams are input into a third parametric amplifier together to output a third output beam and a fourth output beam, the first output beam is input into a first balanced homodyne detection system to output a first output signal, the second output beam is input into a second balanced homodyne detection system to output a second output signal, the third output beam is input into a third balanced homodyne detection system and then outputs a third output signal, the fourth output beam is input into a fourth balanced homodyne detection system and then outputs a fourth output signal, and the fourth output signal is simultaneously input into a data acquisition and operation system (11) and is operated as follows: the first output signal and the fourth output signal are added, the second output signal and the third output signal are added, the third output signal and the first output signal are subtracted, the fourth output signal and the second output signal are subtracted, four paths of signals are output after operation, and the four paths of signals are input into an information display system (12) to analyze the transmission coefficient.

The invention has the beneficial effects that:

1. the invention realizes the noiseless beam splitting of twin double-beam coded quantum information by combining the entanglement source with the optical parametric amplifier, and can be simultaneously provided for four users.

2. The invention can be used in cascade by taking two output light beams of the two optical parametric amplifiers as input light of the same device, thereby increasing the number of users.

Drawings

FIG. 1 is a schematic diagram of an entanglement state-based quantum information beam splitting device suitable for twin double-beam encoding.

Detailed Description

The present invention will be further described with reference to the following examples and drawings, but the scope of the present invention should not be limited thereto.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an embodiment of an entanglement state-based quantum information beam splitting device suitable for twin dual-beam encoding according to the present invention. The quantum information beam splitting device based on the entangled state is suitable for twin double-beam coding and comprises a first optical parametric amplifier 1, a phase modulator 2, a coarse wavelength division multiplexer 3, an entangled source 4, a second optical parametric amplifier 5, a third optical parametric amplifier 6, a first balanced homodyne detection system 7, a second balanced homodyne detection system 8, a third balanced homodyne detection system 9, a fourth balanced homodyne detection system 10, a data acquisition and operation system 11 and an information display system 12.

The first optical parametric amplifier 1 generates a pair of twin beams having entanglement characteristics, different frequencies, and being spatially co-propagating. The twin double light beam passes through a phase modulator 2, the phase is modulated to carry information, and the twin double light beam carrying the information is spatially separated by a coarse wavelength division multiplexer 3 to form two light beams. The entanglement source generates a pair of light beams having entanglement characteristics, wherein a first light beam has the same frequency and spatial pattern as a second light beam of the twin light beams, and the other light beam has the same frequency and spatial pattern as the first light beam of the twin light beams. The first beam of the twin beams and the first beam of the entangled beams are inputted into a second parametric amplifier 5 together to output a first output beam and a second output beam, and the second beam of the twin beams and the other beam of the entangled beams are inputted into a third parametric amplifier 6 together to output a third output beam and a fourth output beam. The first output beam is input into a first balanced homodyne detection system 7, the second output beam is input into a second balanced homodyne detection system 8, the third output beam is input into a third balanced homodyne detection system 9, and the fourth output beam is input into a fourth balanced homodyne detection system 10. The four balanced homodyne detection systems are respectively composed of a 50:50 beam splitter, the background light and the corresponding measured light beams have the same frequency, space and polarization mode, the two output light beams of the 50:50 beam splitter are detected by two photodiodes to output photocurrent, the photocurrent is converted into a voltage signal after being subtracted, and the voltage signal is used as the output of the balanced homodyne detection system after being filtered and amplified.

The first balanced homodyne detection system 7, the second balanced homodyne detection system 8, the third balanced homodyne detection system 9 and the fourth balanced homodyne detection system 10 respectively output a first output signal, a second output signal, a third output signal and a fourth output signal, and the four output signals are simultaneously input into the data acquisition and operation system 11 for the following operations: the first output signal and the fourth output signal are added, the second output signal and the third output signal are added, the third output signal and the first output signal are subtracted, the fourth output signal and the second output signal are subtracted, and four paths of signals are output after operation. The four-way signal is input to the information display system 12 for analysis of the transmission coefficient.