Open AccessInfluence of feedback strength on the characteristics of the random number sequence extracted from an external-cavity feedback semiconductor laser
Author(s) -
Haibo Yang,
Xia Guang-Qiong,
Tang Xi,
Jiagui Wu,
Ziyan Wu
Publication year - 2015
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.64.084204
Subject(s) - randomness , chaotic , pseudorandom binary sequence , semiconductor laser theory , approximate entropy , entropy (arrow of time) , binary number , computer science , physics , laser , control theory (sociology) , optics , mathematics , quantum mechanics , statistics , artificial intelligence , control (management) , arithmetic
Under proper feedback strength, an external-cavity feedback semiconductor laser can operate at a chaos state, and its chaotic output can be used as a physical entropy source to generate a physical random number sequence. In this paper, we focus on the influence of feedback strength on the randomness of the obtained binary code sequence. The simulation results show that with the increase of feedback strength, the time delay characteristic peak of the chaotic signal from an external-cavity feedback semiconductor laser first decreases and then increases gradually, meanwhile, the permutation entropy characteristic value of chaotic signal first increases and then decreases gradually, namely, there exists an optimized feedback strength for obtaining the chaotic signal with the weakest time delay signature and high complexity. The randomness of binary code sequences, generated by the chaotic signal from the external-cavity feedback semiconductor laser under different feedback strengths, is tested by NIST Special Publication 800-22, and the influence of feedback strength on the test results is also discussed.