Single-longitudinal-mode, narrow bandwidth double-ring fiber laser stabilized by an efficiently taper-coupled high roundness microsphere resonator. (June 2018)

• Record Type: Journal Article
• Authors: Wan, Hongdan; Liu, Linqian; Ding, Zuoqin; Wang, Jie; Xiao, Yu; Zhang, Zuxing
• Is Part Of: Optics & laser technology. Volume 102(2018)
• Page Start: 160
• Page End: 165
• Publication Date: 2018-06
• Subjects: Fiber laser -- Single-longitudinal-mode -- Whispering gallery mode -- Microsphere resonator; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2017.12.039
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Fiber laser mode selected by a stable packaged ultra-high roundness microsphere. Laser has a bandwidth of <0.01 nm and a signal-to-background ratio of 54 dB. Microsphere fabrication, coupling condition are optimized for high Q WGM spectra. The single-longitudinal-mode laser is useful for optical communication and sensors. Abstract: This paper proposes and demonstrates a single-longitudinal-mode, narrow bandwidth fiber laser, using an ultra-high roundness microsphere resonator (MSR) with a stabilized package as the single-longitudinal-mode selector inside a double-ring fiber cavity. By improving the heating technology and surface cleaning process, MSR with high Q factor are obtained. With the optimized coupling condition, light polarization state and fiber taper diameter, we achieve whispering gallery mode (WGM) spectra with a high extinction ratio of 23 dB, coupling efficiency of 99.5%, a 3 dB bandwidth of 1 pm and a side-mode-suppression-ratio of 14.5 dB. The proposed fiber laser produces single-longitudinal-mode laser output with a 20-dB frequency linewidth of about 340 kHz, a signal-to-background ratio of 54 dB and a high long-term stability without mode-hopping, which is potential for optical communication and sensing applications.