Harith Ahmad, Leela Wanti Lohano, Bilal Nizamani, Mousa Hussein, Shufeng Sun, Kavintheran Thambiratnam
In this work, a multi- and dual-wavelength fiber laser is experimentally demonstrated for the first time using a six-mode fiber-based inline comb filter in the S-band. The six-mode fiber filter (6MFF) is fabricated by manual core-offset splicing of a single-mode fiber to a six-mode fiber. This technique generates a comb-like transmission spectrum having a free spectral range of 0.21 nm. The 6MFF provides a comb-like wavelength filtering, whereas a 10 km dispersion-compensating fiber (DCF) is integrated into the cavity to ensure spectral stability by suppressing mode competition. At the same time, it produces additional lasing lines via four-wave mixing. Hence, a multi-wavelength fiber laser with 20 stable lasing lines spanning 1502.34 to 1506.30 nm is obtained by incorporating the 6MFF and DCF. The optical spectrum demonstrates optimal stability, with an optical signal-to-noise ratio (OSNR) ranging from 38 to 44 dB and with power and wavelength drifts of <0.6dB and 0.1 nm, respectively. In addition, dual-wavelength operation at 1502.41 nm and 1502.61 nm is achieved with an OSNR of ∼50dB by inserting a tunable bandpass filter into the cavity. Continuous tunability over 36 nm is observed from 1470 to 1506 nm. The proposed laser offers high stability and low system complexity, making it suitable for applications in dense wavelength-division multiplexing, millimeter-wave generation, and fiber sensing. © 2026 Society of Photo-Optical Instrumentation Engineers (SPIE)
Universiti Malaya, Photonics Research Centre, Kuala Lumpur, Malaysia; Universiti Malaya, Faculty of Science, Physics Department, Kuala Lumpur, Malaysia; Universitas Negeri Malang, Faculty of Mathematics and Natural Sciences, Department of Physics, Malang, Indonesia; Universiti Malaya, Institute for Advanced Studies, Kuala Lumpur, Malaysia; United Arab Emirates University, Department of Electrical and Communication Engineering, Al Ain, United Arab Emirates; Qingdao University of Technology (QUT), School of Mechanical & Automotive Engineering, Qingdao, China; International Islamic University of Malaysia, Physics Department, Kulliyyah of Science, Kuantan, Malaysia
