A method and system for generating chaotic laser generation with high bandwidth and time delay tag concealment

Abstract

The invention provides a method and system for generating chaotic laser generation with high bandwidth and time delay tag concealment. In the feedback cavity of the traditional external cavity semiconductor laser, the phase modulation module and the delay fiber interferometer are added in turn. The output chaotic laser is used as the RF input of the phase modulator after photoelectric conversion and amplification, and the self-chaotic phase modulation structure is formed. The invention has the advantages that the generation of the wide-band chaotic laser, the concealment of the time delay label and the symmetrical amplitude distribution are simultaneously realized.

Description

technical field [0001] The invention relates to a generation scheme of broadband chaotic laser, in particular to a method and system for generating chaotic laser with high bandwidth and time delay label hiding. Background technique [0002] Chaotic laser has important applications in the fields of secure communication, high-speed physical random number generation, and high-resolution anti-jamming radar detection. Using the wide-band and large-amplitude chaotic laser as the carrier wave to hide the information, and then using the chaos synchronization to demodulate the information, can realize the encrypted communication of high-speed information; because of its high bandwidth and large-amplitude noise-like characteristics, the chaotic laser is used as a new generation of physics The entropy source is used to solve the problem of insufficient real-time generation rate of physical random numbers; the radar system is constructed by using broadband chaotic laser as a signal sour...

AI Technical Summary

Problems solved by technology

However, after in-depth research, scholars have found that there are some defects in the chaotic laser generated by the external cavity semiconductor laser: (1) The external cavity semiconductor laser has obvious relaxation oscillations. From the observation of the power spectrum, the main energy of the chaotic laser is concentrated in the relaxation Therefore, the effective bandwidth and flatness of the power spectrum are limited; (2) due to the existence of external cavity resonance, the autocorrelation curve of the generated chaotic signal has an obvious correlation peak at the external cavity period, which is called is the time delay label; (3) The chaotic laser amplitude oscillation generated by the external cavity semiconductor laser is not balanced, and the amplitude distribution presents obvious asymmetry

The existence of these defects limits the practical application

In secure communication, the relaxation oscillation causes the bandwidth of chaotic laser to be only a few GHz. This limited bandwidth will limit the transmission rate of chaotic optical communication; at the same time, the time delay characteristic leaks the length of the external cavity, which leads to the interception to use this key structural information. Reconstruct the chaotic carrier signal, and then crack the transmitted information, weakening the security of the communication system

In the generation of physical random numbers, the limited entropy source bandwidth limits the rate of generated physical random numbers; the delay characteristics and asymmetric amplitude distribution deteriorate the randomness and equilibrium ratio of 0 and 1 bits respectively, requiring the use of complex follow-up processing for optimization

In terms of radar detection, limited bandwidth limits the improvement of chaotic laser detection distance resolution; time delay characteristics also reduce the security and anti-interference ability of radar systems

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