Passively Q-switched dual-wavelength thulium-doped fiber laser based on a multimode interference filter and a semiconductor saturable absorber. (2nd March 2018)

• Record Type: Journal Article
• Authors: Wang, M; Huang, Y J; Ruan, S C
• Is Part Of: Laser physics. Volume 28:Number 4(2018:Apr.)
• Publication Date: 2018-03-02
• Subjects: passively Q-switched -- dual-wavelength -- theta cavity -- single-mode-multimode-single-mode fiber structure; Lasers -- Periodicals; 621.36605
• DOI: 10.1088/1555-6611/aaa5d0
• Languages: English
• ISSNs: 1054-660X

Abstract

Abstract: In this paper, we have demonstrated a theta cavity passively Q-switched dual-wavelength fiber laser based on a multimode interference filter and a semiconductor saturable absorber. Relying on the properties of the fiber theta cavity, the laser can operate unidirectionally without an optical isolator. A semiconductor saturable absorber played the role of passive Q-switch while a section of single-mode-multimode-single-mode fiber structure served as an multimode interference filter and was used for selecting the lasing wavelengths. By suitably manipulating the polarization controller, stable dual-wavelength Q-switched operation was obtained at ~1946.8 nm and ~1983.8 nm with maximum output power and minimum pulse duration of ~47 mW and ~762.5 ns, respectively. The pulse repetition rate can be tuned from ~20.2 kHz to ~79.7 kHz by increasing the pump power from ~2.12 W to ~5.4 W.