Phase decoding method, phase decoding device and quantum secret key distribution system

A technology of a decoding device and a decoding method, which is applied in the field of optical transmission secure communication, can solve problems such as low system efficiency and large interference ring loss, and achieve the effects of improving system efficiency, low insertion loss, and reducing insertion loss

Active Publication Date: 2018-01-19
CHINA ACADEMY OF ELECTRONICS & INFORMATION TECH OF CETC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, this kind of interference ring has a large loss, and the insertion loss of the phase modulator is one of the main factors causing the large loss. When the phase modulator is placed in one arm o

Method used

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  • Phase decoding method, phase decoding device and quantum secret key distribution system
  • Phase decoding method, phase decoding device and quantum secret key distribution system
  • Phase decoding method, phase decoding device and quantum secret key distribution system

Examples

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no. 1 example

[0045] In the first embodiment of the present invention, a phase decoding method, such as figure 1 As shown, it specifically includes the following steps:

[0046] Step S101: polarization-splitting an incoming input light pulse into a first transmission light pulse and a second transmission light pulse.

[0047] Specifically, the polarization state of the incident input light pulse may be any polarization state, and the polarization states of the first transmission light pulse and the second transmission light pulse after polarization splitting are orthogonal to each other.

[0048] Step S102: Perform phase decoding on the first transmission optical pulse and the second transmission optical pulse respectively, and each transmission optical pulse obtains two sub-output optical pulses after phase decoding.

[0049]Specifically, the phase decoding of the first transmission optical pulse and the second transmission optical pulse includes:

[0050] Splitting one transmission opti...

no. 3 example

[0072] In the third embodiment of the present invention, a phase decoding device, such as image 3 As shown, it specifically includes the following components: a polarization beam splitter 301 , two phase decoders 302 and 303 , and two polarization beam combiners 304 and 305 .

[0073] The polarization beam splitter 301 polarizes and splits one input light pulse into two transmission light pulses. One transmission optical pulse undergoes phase decoding by the phase decoder 302 to obtain two sub-output optical pulses; the other transmission optical pulse undergoes phase decoding by the phase decoder 303 to obtain the other two sub-output optical pulses. One output optical pulse of the phase decoder 302 and one output optical pulse of the phase decoder 303 are combined into an output through the polarization beam combiner 304; the other output optical pulse of the phase decoder 302 and the output optical pulse of the phase decoder 303 The other output light pulses are combined ...

no. 5 example

[0076] The fifth embodiment of the present invention, an unequal arm Mach-Zehnder interference ring, such as Figure 5 As shown, it specifically includes the following components: two 2×2 3dB beam splitters 503 and 506 , a delay line 504 , and a phase modulator 505 .

[0077] One of the two ports 501 and 502 on one side of the 3dB beam splitter 503 is used as the input end of the phase encoder, and one of the two ports 507 and 508 on the other side of the 3dB beam splitter 506 is used as the output end of the phase encoder , the delay line 504 and the phase modulator 505 are respectively inserted into the two arms of the Mach-Zehnder interference ring. When working, the optical pulse enters the beam splitter 503 through the port 501 or 502 of the beam splitter 503 and is divided into two paths for transmission. One path is delayed by the delay line 504, and the other path is phase modulated by the phase modulator 505. The optical pulses transmitted on the two optical paths ar...

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Abstract

The invention provides a phase decoding method, a phase decoding device and a quantum secret key distribution system. The method includes splitting an incident input light pulse into a first transmission light pulse and a second transmission light pulse through polarization; performing phase decoding on the first transmission light pulse and the second transmission light pulse respectively, wherein two sub output light pulses are acquired after phase decoding of each transmission light pulse; combing any sub output light pulse of the first transmission light pulse after phase decoding with anysub output light pulse of the second transmission light pulse after phase decoding into an output light pulse through polarization. By the method, influences of random light pulse polarization statechanges on system stability can be effectively solved, and stable phase decoding of environmental disturbance immunity of transmission optical fibers is realized. An unequal-arm Mach-Zundel interference ring is adopted, and light pulses only need to pass a phase modulator once during decoding, so that insertion losses of a receiving terminal are reduced greatly, and system efficiency is improved remarkably.

Description

technical field [0001] The invention relates to the technical field of optical transmission secure communication, in particular to a phase decoding method, device and quantum key distribution system. Background technique [0002] In the phase-encoded quantum key distribution system based on unequal arm interference rings, during the transmission of optical pulses in optical fiber quantum channels, there are non-ideal conditions such as non-circular symmetry in the cross-section of the optical fiber and uneven distribution of the core refractive index along the radial direction. , and the optical fiber is affected by temperature, strain, bending, etc. in the actual environment, resulting in birefringence effect. The increase and deterioration are obvious. In the prior art, an unequal-arm Faraday-Michelson interference ring is proposed, which can prevent the polarization state of the optical pulse from being affected by the random birefringence of the optical fiber channel, a...

Claims

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Application Information

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IPC IPC(8): H04L9/08
CPCH04L9/08
Inventor 许华醒谢海永廖勇莫小范程旭升
Owner CHINA ACADEMY OF ELECTRONICS & INFORMATION TECH OF CETC
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