Research On Key Technologies Of Silicon-based Vacuum Quantum Random Number Generator

Quantum random number generator can theoretically generate unpredictable and non-replicable random numbers by using the non-deterministic physical process of uncertainty principle in quantum mechanics,which can guarantee the security of important information.Therefore,it is widely used in the field of information security.The quantum state of the continuous variable quantum random number generator based on vacuum fluctuation is easy to prepare.Then the detection device is simple and the generation rate is high.Finally,it is not easy to be controlled by the potential attacker,and the security is strong.In recent years,the continuous variable quantum random number generator based on vacuum fluctuation has been developed rapidly and is gradually commercialized.However,the vacuum fluctuation quantum random number generator composed of discrete optical devices is difficult to integrate into other complex systems in size,and its application in practical scenes is seriously limited by high cost,high power consumption and instability.Compared with ordinary optical systems,the integrated optical circuit has many advantages,such as wide signal band,small size,light weight,low power consumption,low cost,strong confidentiality,etc.It is a good integration platform.At the same time,many optical devices based on silicon-based optoelectronic technology have been realized one by one,so the idea of integrating vacuum fluctuation quantum random number generators into silicon on insulator with integrated circuits is no longer out of reach.However,there are still some technical problems in practical implementation,such as noise control in the system,wire bonding of silicon chip and coupling between laser and chip.In order to study and solve these technical problems,the main work and innovation results of this paper are as follows:1、A vacuum fluctuation quantum random number generator system based on silicon chip is established in the laboratory.The area of silicon chip is less than 1 square centimeter.After investigation and experimental study,the connection between silicon chip and trans-impedance amplifier is solved by wire bonding and sandwich PCB,and the noise introduced by the connection is reduced,so that the noise does not affect the measurement of the signal.Then,the circuit structure of the trans-impedance amplifier is optimized according to the quantum random number generator scheme on the silicon chip,so that multiple vacuum fluctuation quantum random number generator schemes on chip can share a trans-impedance amplifier.This method can prevent the problem of experimental termination due to the damage of integrated devices and make effective use of trans-impedance amplifiers.Lastly,based on the quantum random number generator system,a scheme to determine whether the laser is coupled into the chip is constructed by using bare fiber,arbitrary signal generator and amplitude modulator,which solves the problem of laser coupling.2、In the experiment,after debugging and optimizing of the system,the system runs stably.In the silicon-based vacuum fluctuation QRNG,the ratio of quantum noise to electrical noise of is 11 dB,and the minimum entropy can reach 8.5 bit.Subsequently,the Toeplitz algorithm is used to extract random sequence from the raw data.The extraction rate can reach 340 Mbps,and the extracted random sequence passes all NIST tests.