Koo, J. Song, Y-W Lee, J. H. 2024-01-20T10:03:12Z 2024-01-20T10:03:12Z 2021-09-05 2014-04 1054-660X https://pubs.kist.re.kr/handle/201004/126952 We propose a carbon nanotube (CNT)-embedded fiber-optic tunable coupler as a passive Q-switch that can provide flexible control of the output pulse repetition rate in passively Q-switched fiber lasers, and experimentally demonstrate its feasibility. The device is implemented by sandwiching a thin CNT layer between two side-polished fibers. Using the coupler, it was experimentally shown that repetition-rate-tunable Q-switched pulses can readily be produced from an erbium-doped fiber ring cavity by adjusting the cross-coupling ratio through control of the core alignment mismatch angle between the two side-polished fibers. Flexible tuning of the pulse repetition rate is shown to be achievable from 20.96 to 12.98 kHz at a fixed pump power by adjusting the core alignment mismatch angle while the pulse width is varied from 4.98 to 5.44 mu s. English IOP PUBLISHING LTD A carbon nanotube-embedded fiber-optic tunable coupler for flexible repetition rate control of a passively Q-switched fiber laser Article 10.1088/1054-660X/24/4/045105 1 LASER PHYSICS, v.24, no.4 LASER PHYSICS 24 4 scie scopus 000333254000006 2-s2.0-84898984065 Optics Physics, Applied Optics Physics Article fiber lasers Q-switching carbon nanotube