A device and method for realizing automatic balance of a balance detection system

Abstract

The invention discloses a device and method for realizing the automatic balance of a balance detection system. The device includes an adjustable beam splitting ratio 2×2 optical fiber coupler connected in sequence, a balanced amplifying photoelectric detection circuit and a signal acquisition circuit, and the signal acquisition circuit is sequentially connected. It is connected with a signal processing circuit, an adjustable beam splitting ratio 2×2 fiber coupler drive circuit and an adjustable beam splitting ratio 2×2 fiber coupler. Compared with the prior art, the positive effects of the present invention are: (1) the device of the present invention is simple in structure, small in size and easy to integrate; (2) the adjustable beam splitting ratio 2×2 fiber optic coupler has high adjustment accuracy and fast response speed It is fast and stable, and can quickly and accurately realize automatic balance adjustment, so that the system can work stably for a long time; (3) The device requires less components, the system complexity is low, and the control circuit and drive circuit are simple in structure and easy to implement.

Description

technical field [0001] The invention relates to a device and method for realizing automatic balance of a balance detection system. Background technique [0002] With the development of modern science and technology, people pay more and more attention to the security of information. Quantum key distribution is based on the basic principles of quantum mechanics (Heisenberg's uncertainty principle and quantum non-cloning theorem, etc.), and any third-party eavesdropping behavior can be detected during the key transmission process, so that both legal communication parties can Share an unconditionally secure set of keys offsite. Continuous variable quantum key distribution (CVQKD) technology has attracted extensive attention in the industry because of its potential high bit rate and good compatibility with classical optical communication. [0003] The balanced detector is the core module of the receiving end in the CVQKD system, and its noise size, stability and balance directl...

AI Technical Summary

Problems solved by technology

Since there is no fixed function curve between temperature change and intensity adjustment, and it is not monotonous, the control is difficult; in addition, the power consumption required for temperature control is relatively large. Under the premise that the fan is not used in order to avoid vibration, the use of Conduction heat dissipation will also lead to an increase in the complexity of the system design; moreover, temperature is a slow variable, and the rapid balance of the detector arms cannot be achieved by temperature control, so it is difficult to achieve the balance of the arms by temperature control. Application Requirements of Key Distribution System

The MEMS electronically controlled attenuator has a simple structure and is easy to integrate. However, the MEMS electronically controlled attenuator is affected by factors such as environmental vibration, process defects, or dust particles. There is a probability that the movable teeth and the static teeth will be engaged or self-stuck during operation, and there are reliability problems.

The automatic control attenuator based on the principle of bending optical fiber uses a linear stepping motor as the driving device for bending optical fiber, which has high precision and stability, but its volume is large, it is not easy to integrate, and the response speed is second level, it is difficult to achieve fast adjust

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