Observation of soliton and bound soliton in erbium-doped fiber lasers using single-walled carbon nanotubes mode-lockers under gamma irradiation

Abstract

This study looked into the generation of soliton and bound-state soliton passively mode-locked Erbium-doped fiber lasers (EDFLs) using gamma (γ) ray irradiated single-walled carbon nanotubes-poly(ethylene oxide) (SWCNT-PEO) film as a saturable absorber (SA). Using the liquid phase exfoliation method, a free-standing SWCNT-PEO film-based SA was developed. The SWCNT-PEO film was non-irradiated before being integrated into the laser cavity, and then subjected to a series of low dose radiations of 50 Gy, 100 Gy, and 200 Gy. The non-irradiated film generated a soliton mode-locked pulsed fiber laser operating at 1560 nm, with a repetition rate of 23.8 MHz and a pulse width of 0.60 ps. Irradiated films of 50 Gy and 100 Gy produced bound-state solitons with pulse separations of 7.68 ps and 2.62 ps, respectively. A soliton mode-locked pulsed fiber laser with an operating wavelength of 1556 nm and a pulse width of 0.59 ps is produced for the 200 Gy irradiated film.