Laser chaotic spread spectrum transformation system with time-delay hiding characteristic

Abstract

The invention discloses a laser chaotic spread spectrum transformation system with a time-delay hiding characteristic. Chaotic optical signals generated by an external cavity semiconductor laser are subjected to spread spectrum transformation through a time lens composed of an optical phase modulator and a high-dispersion medium; specifically speaking, chaotic spectrum broadening is realized through increasing dispersion quantity based on a situation that time-domain Fourier transformation performs time-frequency conversion; time delay tag hiding is realized through adjusting the relationship of a driving signal period and chaotic laser feedback delay time; and chaotic optical signals are outputted according to the noise type of the chaotic signals after the spread spectrum transformation is performed, and therefore, a spectrum can be flat and has large effective bandwidth.

Description

technical field [0001] The invention belongs to the technical field of lasers, and more specifically relates to a laser chaotic spread-spectrum conversion system with time-delay hiding characteristics. Background technique [0002] In recent years, major breakthroughs have been made in the application of chaotic lasers generated by external cavity lasers in secure communication, random key generation and other fields. With the deepening of research, the disadvantages of chaotic laser signals of external cavity lasers are gradually revealed: on the one hand, most of the energy in the spectrum of chaotic laser signals is concentrated near the relaxation oscillation frequency of the laser, resulting in uneven spectrum and limited effective bandwidth; On the one hand, due to the resonance characteristics of the external feedback cavity, the chaotic laser signal of the external cavity laser has obvious autocorrelation at the feedback delay. The above two defects restrict the sec...

AI Technical Summary

Problems solved by technology

With the deepening of research, the disadvantages of chaotic laser signals of external cavity lasers are gradually revealed: on the one hand, most of the energy in the spectrum of chaotic laser signals is concentrated near the relaxation oscillation frequency of the laser, resulting in uneven spectrum and limited effective bandwidth; On the one hand, due to the resonance characteristics of the external feedback cavity, the chaotic laser signal of the external cavity laser has obvious autocorrelation at the feedback delay

The above two defects restrict the security of chaotic secure communication, and also limit the rate of generating random keys and the randomness of keys

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