Tunable passively Q-switched ultranarrow linewidth erbium-doped fiber laser

• Main Authors: M.Z. Zulkifli, F.D. Muhammad, M.F. Mohd Azri, M.K. Mohd Yusof, K.Z. Hamdan, S.A. Samsudin, M. Yasin
• Format: Article
• Language: English
• Published: Elsevier 2020-03-01
• Series: Results in Physics
• Subjects: Ultra-narrow linewidth; Tunable wavelength; Passively Q-switched and erbium; Doped fiber laser
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211379719333327

A tunable passively Q-switched erbium-doped fiber laser with ultranarrow linewidth is proposed and demonstrated. With the single wall carbon nanotubes (SWCNTs) as the passive Q-switch, the ultranarrow linewidth laser operation is realized based on spectral filtering effect.using an ultranarrow tunable bandpass filter (UNTBF). The Q-switched laser spectrum is tunable from 1525 to 1561 nm, covering a wavelength range of 36 nm. At 1545 nm, the highest repetition rate of ~38 kHz and the lowest pulse width of 1.15 μs are obtained, with the corresponding pulse energy of approximately 0.18 nJ. The linewidth measurement using self-heterodyne technique yields a linewidth value of 17.5 kHz, which may be the narrowest linewidth for a Q-switched fiber laser to the best of our knowledge.