H. Ahmad, B. Nizamani, M.Z. Samion, M. Yasin
Dual-wavelength fiber lasers have gained the interest of researchers in practical applications such as fiber-optic sensors and optical telecommunication. This work demonstrated a broadly tunable dual-wavelength thulium-doped fluoride fiber laser (TDFFL) at the S-band region. Two tunable-bandpass filters (TBPFs) were incorporated in the TDFFL cavity to achieve dual-wavelength fiber laser (DWFL) operation. Two identical peaks with a balanced signal-to-noise ratio (SNR) were acquired by tuning TBPFs and an attenuator within the cavity. The DWFL covers a significant portion of S-band TDFFL gain from 1472.9 to 1506.5 nm with a wide tunability in wavelength spacing from 0.95 to 33.6 nm. The narrowest possible DWFL was achieved with the spacing of 0.95 nm at the operating wavelengths of 1489.2 and 1490.15 nm, with a frequency bandwidth of 128 GHz. The broadest spacing of 33.6 nm was achieved at operating wavelengths of 1472.9 and 1506.5 nm, with a frequency bandwidth of 4.79 THz. © 2023 Elsevier Inc.
Photonics Research Centre, Universiti Malaya, Kuala Lumpur, 50603, Malaysia; Physics Department, Faculty of Science, Universiti Malaya, Kuala Lumpur, 50603, Malaysia; Visiting Distinguished Professor, Universiti Kuala Lumpur British Malaysian Institute (UniKL BMI), Batu 8, Jln Sungai Pusu, Selangor, 53100, Malaysia; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Malang, 65145, Indonesia; Department of Physics, Faculty of Science and Technology, Airlangga University, Surabaya, 60115, Indonesia