High-speed and high-tunable bandwidth quantum-balanced homodyne detector and its control method

Abstract

The invention provides a high-speed high-adjustable bandwidth quantum balance homodyne detector and a control method thereof. The detector comprises a coherent interference part, a high-speed balancehomodyne detection part, a trans-impedance amplifier part, a second-stage high gain bandwidth product amplifier part, a filter circuit part and a semiconductor refrigerator, wherein the coherent interference part is used for outputting two optical signals with an accurate 50:50 splitting ratio via adjusting a variable attenuator after weak quantum signal light and high-strength local oscillation light are subjected to interference on a light beam separator; and the high-speed balance homodyne detection part is used for separately converting the size of light strength into the size of currentsaccording to certain efficiency and proportions on two PIN photodiodes, and converging the two optical currents to acquire a differential current. According to the detector and the control method thereof provided by the invention, the bandwidth, response speed and stability of detection are improved.

Description

technical field [0001] The invention relates to a homodyne detector and a control method thereof, in particular to a high-speed and high-adjustable bandwidth quantum balance homodyne detector and a control method thereof. Background technique [0002] With the rapid development of computer information technology and the increasing severity of password deciphering methods and multi-way virus intrusion, the requirements of information technology for information security are increasing day by day. In recent years, due to the characteristics of the uncertainty principle and unclonability of quantum physics, the use of quantum for key distribution has attracted extensive attention from researchers. [0003] Quantum key distribution technology mainly includes discrete variable quantum key distribution and continuous variable quantum key distribution. The research on discrete variable quantum key distribution started earlier and is more mature. Continuous variable quantum key dis...

AI Technical Summary

Problems solved by technology

The bandwidth, response rate, and stability of balanced homodyne detectors are all issues that need to be considered in practical problems, but the bandwidth of current balanced homodyne detectors is usually low, the responsivity is not too high, shot noise and electrical noise The ratio of is usually lower than 10dB, which restricts the detection performance of the detector, thereby affecting the stability of the entire communication and reducing the efficiency of the communication

Traditional balanced homodyne detectors are usually limited by low bandwidth and low response rate, these factors restrict the repetition rate of the system, thereby restricting the key rate of detection

At the same time, traditional balanced homodyne detectors usually have large electrical noise, which affects the detection of shot noise, and the low shot noise and electrical noise ratio will restrict the transmission distance of continuous variable quantum key distribution

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