Open AccessCompact all-fiber 21-27 μm tunable Raman soliton source based on germania-core fiber
Author(s) -
Yanhong Li,
Tao Du,
Bin Xu,
Hao Xu,
Zhiping Cai,
Valery M. Mashinsky,
Zhengqian Luo
Publication year - 2019
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.028544
Subject(s) - fiber laser , optics , ultrashort pulse , femtosecond , materials science , raman spectroscopy , laser , dispersion shifted fiber , fiber , photonic crystal fiber , core (optical fiber) , polarization maintaining optical fiber , optoelectronics , optical fiber , physics , fiber optic sensor , composite material
Although ultrafast rare-earth-doped fiber lasers mode-locked at near-infrared and ∼3 μ m wavelengths have been well developed, it is relatively difficult to achieve ultrafast fiber laser emitting in the 2.1-2.7 μ m spectral gap between ∼2 μ m (Tm fiber) and ∼2.8 μ m (Er or Ho fluoride fiber). In this paper, we report the generation of 2.1-2.7 μ m tunable femtosecond Raman solitons from a compact fusion-spliced all-fiber system using a home-made 1.96 μ m ultrafast pump source and a MIR-available germania-core fiber. At first, a Tm-doped double-clad fiber amplifier is used to not only boost up the power of 1957 nm femtosecond seed laser, but also to generate the first-order soliton self-frequency shift (SSFS). The first-order Raman solitons can be tuned from 2.036 to 2.152 μ m, have a pulse duration of ∼480 fs and can reach a pulse energy of 1.07 nJ. The first-order Raman solitons are further injected into a 94 mol. % germania-core fiber to excite the second-order SSFS. The second-order solitons can be tuned to longer wavelengths, i.e. from 2.157 μ m up to 2.690 μ m. Our work could provide an effective way to develop compact, all-fiber ultrafast MIR laser sources with the continuous wavelength tuning of 2.1-2.7 μ m.