Flat Broadband Chaos Generation Using a Semiconductor Laser Subject to Asymmetric Dual-Path Optical Feedback

• Published in: Journal of lightwave technology Vol. 39; no. 19; pp. 6246 - 6252
• Main Authors: Yang, Qiang, Qiao, Lijun, Wei, Xiaojing, Zhang, Boxin, Chai, Mengmeng, Zhang, Jianzhong, Zhang, Mingjiang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Asymmetry; Band-pass filters; Bandpass filters; Bandwidth; Bandwidths; Broadband; Broadband chaos; Chaos; dual-path optical feedback; flat spectrum; Flatness; Optical attenuators; Optical feedback; Optical fibers; Optical polarization; Semiconductor lasers; Spectrum allocation
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2021.3095972

A method of generating flat broadband chaos by using a semiconductor laser subject to asymmetric dual-path optical feedback is proposed and demonstrated experimentally. In the asymmetric dual-path optical feedback, one path is connected with an optical band-pass filter (OBPF) to form filtered path, and the other is a traditional optical feedback path named non-filtered path. Through the beating frequency effect between the filtered mode and the non-filtered chaos mode, a chaotic signal with the standard bandwidth of 36.1 GHz and the spectrum flatness of 5.8 dB is generated experimentally. Furthermore, the effects of filter frequency detuning, filter bandwidth and feedback strength on the bandwidth and flatness of chaos are investigated. The results show that the bandwidth enhancement and the flat spectrum can be achieved simultaneously in a wide range of operating parameters.