Open AccessAll-normal dispersion supercontinuum vs frequency-shifted solitons pumped at 1560 nm as seed sources for thulium-doped fiber amplifiers
Author(s) -
Olga Szewczyk,
Karol Tarnowski,
Aleksander Głuszek,
Daniel Szulc,
Karolina Stefańska,
Paweł Mergo,
Grzegorz Soboń
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.430292
Subject(s) - supercontinuum , optics , materials science , fiber laser , femtosecond , dispersion (optics) , self phase modulation , laser , amplifier , ultrashort pulse , dispersion shifted fiber , optoelectronics , optical fiber , nonlinear optics , photonic crystal fiber , physics , fiber optic sensor , cmos
We present a direct comparison between two types of femtosecond 2 µm sources used for seeding of an ultrafast thulium-doped fiber amplifier based on all-normal dispersion supercontinuum and soliton self-frequency shift. Both nonlinear effects were generated in microstructured silica fibers, pumped with low-power femtosecond pulses at 1.56 µm originating from an erbium-doped fiber laser. We performed a full characterization of both nonlinear processes, including their shot-to-shot stability, phase coherence, and relative intensity noise. The results revealed that the solitons show comparable performance to supercontinuum in terms of relative intensity noise and shot-to-shot stability, despite the anomalous dispersion regime. Both sources can be successfully used as seeds for Tm-doped fiber amplifiers as an alternative to Tm-doped oscillators. The results show that the sign of chromatic dispersion of the fiber is not crucial for obtaining a stable, high-quality, and low-noise spectral conversion process when pumped with sub-50 fs laser pulses.