Fast random bit generation with bandwidth-enhanced chaos in semiconductor lasers

• Published in: Optics express Vol. 18; no. 6; pp. 5512 - 5524
• Main Authors: Hirano, Kunihito, Yamazaki, Taiki, Morikatsu, Shinichiro, Okumura, Haruka, Aida, Hiroki, Uchida, Atsushi, Yoshimori, Shigeru, Yoshimura, Kazuyuki, Harayama, Takahisa, Davis, Peter
• Format: Journal Article
• Language: English
• Published: United States 15.03.2010
• Subjects: Computer Simulation; Lasers, Semiconductor; Models, Statistical; Nonlinear Dynamics; Signal Processing, Computer-Assisted - instrumentation
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.18.005512

We experimentally demonstrate random bit generation using multi-bit samples of bandwidth-enhanced chaos in semiconductor lasers. Chaotic fluctuation of laser output is generated in a semiconductor laser with optical feedback and the chaotic output is injected into a second semiconductor laser to obtain a chaotic intensity signal with bandwidth enhanced up to 16 GHz. The chaotic signal is converted to an 8-bit digital signal by sampling with a digital oscilloscope at 12.5 Giga samples per second (GS/s). Random bits are generated by bitwise exclusive-OR operation on corresponding bits in samples of the chaotic signal and its time-delayed signal. Statistical tests verify the randomness of bit sequences obtained using 1 to 6 bits per sample, corresponding to fast random bit generation rates from 12.5 to 75 Gigabit per second (Gb/s) ( = 6 bit x 12.5 GS/s).