Tunable passively Q-switched thulium doped fluoride fibre (TDFF) laser using reduced graphene oxide-silver (rGO-Ag) as saturable absorber

• Published in: Journal of modern optics Vol. 67; no. 11; pp. 1022 - 1030
• Main Authors: Ahmad, H., Azmy, N. F., Reduan, S. A., Yusoff, N., Bayang, L., Zulkifli, M. Z., Thambiratnam, K.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 24-06-2020; Taylor & Francis Ltd
• Subjects: Absorbers; Bandpass filters; Fiber lasers; Fluorides; Graphene; Lasers; Noise levels; Q-switched fibre laser; reduced graphene oxide-silver (rGO-Ag); Signal to noise ratio; Silver; Thin films; Thulium; Wavelength tunable system
• ISSN: 0950-0340; 1362-3044
• DOI: 10.1080/09500340.2020.1810340

A tunable, passively Q-switched thulium doped fluoride fibre (TDFF) laser using a reduced-graphene oxide-silver (rGO-Ag) thin film as a saturable absorber (SA) for S band operation is proposed and its efficacy demonstrated. Over a pump power range of 91.4 mW up to 158.6 mW, passively generated Q-switched pulses are observed with repetition rates from 20 to 34.5 kHz and pulse widths from 3.1 to 7.1 µs. The highest pulse energy observed is 101.2 nJ with a signal to noise ratio of ∼42 dB. The proposed laser has a tuning range ∼52 nm from 1458 to 1510 nm with a tunable bandpass filter (TBPF) introduced into the cavity.