Harith Ahmad, Kirubhashni Loganathan, Norazriena Yusoff, Muhamad Zharif Samion, Kavintheran Thambiratnam
This study investigated the impact of arc-shaped fibre structures coated with a composite material on a Thulium/Holmium-doped fibre laser (THDF). Two types of arc-shaped fibres were utilised: single and dual arc. Both arc-shaped fibres were fabricated using the wheel-polishing technique. A two-step polishing process was employed for the dual arc-shaped fibre. The reduced graphene oxide/manganese oxide (rGO/Mn3O4) composite was subjected to hydrothermal treatment and then dropped onto both arc-shaped fibres. The modulation depth of rGO/Mn3O4 in a single arc-shaped fibre was 51.15% and 48.79% for the dual arc. Mode-locked pulses were generated individually by placing the saturable absorbers (SAs) in the cavity and fine-tuning the polarisation controller (PC). The pulse duration was 1.544 ps and 1.634 ps for the single and dual arc-shaped fibres. The two mode-locked pulses produced were remarkably stable, with a signal-to-noise ratio (SNR) exceeding 60 dB. Due to its lower insertion loss, the single arc shape fibre-based SA outperformed the dual arc in various aspects, including SNR, pulse duration, average power, and efficiency. The findings of this work provide a compelling alternative for generating ultrashort pulse lasers that are both compact in size and highly effective in performance. © 2025, National Institute of Optoelectronics. All rights reserved.
Photonics Research Centre, Universiti Malaya, Kuala Lumpur, 50603, Malaysia; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Malang, 65145, Indonesia; Department of Physics, Faculty of Science, Universiti Malaya, Kuala Lumpur, 50603, Malaysia; Physics Department, Kulliyyah of Science, International Islamic University Malaysia, Bandar Indera Makhota, Kuantan, 25200, Malaysia
