Portable light source position automatic calibration system and calibration method

Abstract

The invention provides a portable automatic calibration system and method for position of light source. The automatic calibration system comprises a photoelectric conversion module, a time measuring module, a position offset computation module, a delay control module, a board-level communication interface and a system switch, wherein the photoelectric conversion module is connected with the time measuring module, the position offset computation module is connected with the time measuring module and the delay control module, the system switch is connected with the delay control module, the external interface of the delay control module is a board-level communication interface, the delay control module is connected with a need to calibration of QKD (Quantum Key Distribution) sender device through the board-level communication interface and optical signals output by the QKD sender device are connected to the photoelectric conversion module. All modules are integrated on a single board. The invention additionally provides a calibration method by using the portable automatic calibration system and method for position of light source. The portable automatic calibration system and method for position of light source have advantages that the calibration operation is simple and flexible, the calibration can be repetitively performed, the cost is low, the efficiency is high, the movement is facilitated and the requirements on industrialization and productization are met.

Description

technical field

[0001] The invention relates to the field of quantum secure communication, in particular to a system and method for calibrating the position of a light source in quantum key distribution (QKD), which has the practicability of quantum key distribution equipment in terms of industrialization and productization. Background technique

[0002] The fundamental difference between Quantum Key Distribution (QKD) and the classical key system is that it uses different quantum states of photons as the carrier of the key, and the basic principles of quantum mechanics guarantee that the process cannot be eavesdropped or deciphered. Therefore, a more secure key system is provided.

[0003] In the current practical QKD system, the design of the sender generally includes the main control part and the light source sending part, such as figure 1 shown. The main control part controls the generation of the driving signal of the light source, and the signal is output to the lase...

Examples

Embodiment 1

[0054] This embodiment adopts a QKD system based on polarization coding, BB84 protocol, and decoy light source. The QKD sender needs to send photons of four different polarization states, and each polarization state of photons includes two kinds of signal (signal) state and decoy (decoy) state, that is, a total of 8 kinds of light need to be sent, corresponding to 8 optical pulses, which can be Respectively denoted as h_s, v_s, p_s, n_s, h_d, v_d, p_d, n_d. Among them, the light intensity of the decoy state is weaker than that of the signal state. The QKD sender selects one of the eight light pulses at each light-emitting time according to a fixed period, so from the perspective of the time axis, all the light pulses transmitted on the optical fiber should be synthesized into one beam with a fixed Periodic optical pulse signal; if the relative positions of the optical pulses finally transmitted on the optical fiber are unstable, the positions of the eight optical pulses need ...

Embodiment 2

[0083] This embodiment adopts a QKD system based on polarization coding, B92 protocol, and non-decoy light source. The QKD sender needs to send photons of two different polarization states (H, +), corresponding to two optical pulses, and the positions of the two optical pulses need to be calibrated.

[0084] Step 1: first set the key parameters of the light source drive signal used for calibration of the QKD sender device, including frequency and code pattern. The code pattern of each light source driving signal is as follows:

[0085] The code pattern of the first channel is: 11000,

[0086] The code pattern of the second channel is: 00111;

[0087] Step 2: Perform simple logic settings on the position offset calculation module, such as start signal frequency, stop signal frequency, expected delay value, calibration accuracy, calibration times threshold and other parameters; among them, the stop signal frequency is generally set to the QKD sender The frequency of the light...

technical field

[0001] The invention relates to the field of quantum secure communication, in particular to a system and method for calibrating the position of a light source in quantum key distribution (QKD), which has the practicability of quantum key distribution equipment in terms of industrialization and productization. Background technique

[0002] The fundamental difference between Quantum Key Distribution (QKD) and the classical key system is that it uses different quantum states of photons as the carrier of the key, and the basic principles of quantum mechanics guarantee that the process cannot be eavesdropped or deciphered. Therefore, a more secure key system is provided.

[0003] In the current practical QKD system, the design of the sender generally includes the main control part and the light source sending part, such as figure 1 shown. The main control part controls the generation of the driving signal of the light source, and the signal is output to the lase...

Examples

Embodiment 1

[0054] This embodiment adopts a QKD system based on polarization coding, BB84 protocol, and decoy light source. The QKD sender needs to send photons of four different polarization states, and each polarization state of photons includes two kinds of signal (signal) state and decoy (decoy) state, that is, a total of 8 kinds of light need to be sent, corresponding to 8 optical pulses, which can be Respectively denoted as h_s, v_s, p_s, n_s, h_d, v_d, p_d, n_d. Among them, the light intensity of the decoy state is weaker than that of the signal state. The QKD sender selects one of the eight light pulses at each light-emitting time according to a fixed period, so from the perspective of the time axis, all the light pulses transmitted on the optical fiber should be synthesized into one beam with a fixed Periodic optical pulse signal; if the relative positions of the optical pulses finally transmitted on the optical fiber are unstable, the positions of the eight optical pulses need ...

Embodiment 2

[0083] This embodiment adopts a QKD system based on polarization coding, B92 protocol, and non-decoy light source. The QKD sender needs to send photons of two different polarization states (H, +), corresponding to two optical pulses, and the positions of the two optical pulses need to be calibrated.

[0084] Step 1: first set the key parameters of the light source drive signal used for calibration of the QKD sender device, including frequency and code pattern. The code pattern of each light source driving signal is as follows:

[0085] The code pattern of the first channel is: 11000,

[0086] The code pattern of the second channel is: 00111;

[0087] Step 2: Perform simple logic settings on the position offset calculation module, such as start signal frequency, stop signal frequency, expected delay value, calibration accuracy, calibration times threshold and other parameters; among them, the stop signal frequency is generally set to the QKD sender The frequency of the light...

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