Light source generator used for decoy-state quantum private communication

Abstract

The invention discloses a light source generator used for decoy-state quantum private communication. The light source generator is characterized by being composed of two drive modules and a semiconductor laser, wherein the two drive modules are used for outputting pulse signals with different peak voltages by adjusting the threshold level of a comparer and the gain of an amplifier, and the semiconductor laser is triggered by the pulse signals with different peak voltages to send a light pulse sequence of a light source used for the decoy-state quantum private communication; and each drive module is composed of a JK trigger D, a high-speed comparer Comp and a differential operational amplifier OP. Compared with the prior art, the light source generated by the light source generator disclosed by the invention has completely same central wavelength, line width and a emergent polarization state, thus avoiding the problem of inconsistent optical characteristics caused by use of two semiconductor lasers; and the light source generator is simple in structure, high in integration degree, free from complex optical device matching and clock calibrating, low in cost, and wide in commercialized production and application prospects.

Description

technical field [0001] The invention relates to the technical field of quantum security communication, in particular to a light source generator for decoy state quantum security communication. Background technique [0002] Since the second half of the last century, scientists have gradually established the concept of quantum cryptography based on the "Heisenberg Uncertainty Principle" and "Quantum Uncloning Principle". Quantum cryptography uses a single quantum state as an information carrier. Since a single quantum state cannot be cloned, and any measurement operation will change its quantum state, eavesdroppers cannot obtain any valid information without being discovered. In other words, the legal receiver of information can know that there is eavesdropping in the channel from the change of the quantum state, thereby terminating the communication process. [0003] Quantum key distribution can establish an unconditional security key between two parties in communication, an...

AI Technical Summary

Problems solved by technology

The disadvantages of this decoy-state light source implementation method are: the cost of the intensity modulator is high, additional modulation drive and more accurate time synchronization are required, the system structure is relatively complicated, and the intensity modulator can adjust the polarization of the input light under different intensity modulations. And the wavelength will have different effects, so that the polarization states of the two output beams are inconsistent, which will affect the final bit error rate of the quantum key

Another method is to use two semiconductor lasers to output two laser beams with different intensities through different driving pulses, and then couple them to the same optical fiber through a fiber combiner. The disadvantage of this method of decoy light source is : The cost of using two semiconductor lasers is high, especially the central wavelengths of the two semiconductor lasers cannot be exactly the same, eavesdroppers may distinguish the signal state and the decoy state through wavelength identification, which poses a great threat to the security of the system

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