Observation of flattened power spectrum of chaotic semiconductor laser using an optical filter

• Published in: IET optoelectronics Vol. 13; no. 3; pp. 104 - 108
• Main Authors: Han, Hong, Zhao, Tong, Wang, An Bang, Wang, Da Ming, Wang, Long Sheng, Wang, Yun Cai, Shore, K. Alan
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.06.2019
• Subjects: Bragg frequency; Bragg gratings; chaotic frequency; chaotic light; chaotic radar; chaotic semiconductor laser; external-cavity feedback semiconductor laser; fibre Bragg grating; flattened power spectrum; laser cavity resonators; laser feedback; low-pass energy distribution; optical chaos; optical fibre filters; optical filter; reflectometry; Research Article; semiconductor lasers; spectral bandwidth; spectral flatness; laser cavity resonators; chaotic semiconductor laser; optical chaos; chaotic light; laser feedback; optical filter; chaotic radar; Bragg gratings; spectral bandwidth; Bragg frequency; flattened power spectrum; optical fibre filters; chaotic frequency; semiconductor lasers; low-pass energy distribution; spectral flatness; reflectometry; fibre Bragg grating; external-cavity feedback semiconductor laser
• ISSN: 1751-8768; 1751-8776; 1751-8776
• DOI: 10.1049/iet-opt.2018.5024

The authors experimentally demonstrate that the spectral flatness of chaotic light from an external-cavity feedback semiconductor laser is significantly improved using a fibre Bragg grating. The effects of detuning between the Bragg frequency and chaotic frequency on the bandwidth and spectral flatness are both investigated. The flatness of the power spectrum is enhanced to ±1.4 dB whilst maintaining the spectral bandwidth at around 8 GHz. The experimental results are in accordance with theoretical predictions which also have shown that the spectral flatness decreases initially then increases with increasing the 3 dB bandwidth of grating. A flattened spectrum with a low-pass energy distribution increases the utilisation efficiency of chaotic light in chaotic radar and reflectometry.