Pulse energy enhancement by means of fiber Bragg gratings in actively Q-switched Tm³⁺-doped fiber lasers operating at 2050 nm and 2090 nm

High-pulse-energy actively Q-switched Tm-doped photonic crystal fiber laser operating at 2050 nm with narrow linewidth

“…Further optimization of the setup could be achieved by using a wavelength-selective OC, as it has been shown for standard fibers. 6 The Tm 3+ -doped PCF can also be used in MOPA systems at 2050 nm in the future, in which the pulse width can be determined by the seed in order to achieve higher peak powers.…”

“…5 Using a fiber with a 20 µm Tm 3+doped core in a Q-switched single oscillator, our group reported pulse energies up to 960 µJ, pulse widths of 44 ns, and peak powers of 20.5 kW at a central emission wavelength of 2050 nm, but with a strongly broadened spectrum due to fiber nonlinearities. 6 Tm 3+ -doped photonic crystal fibers (PCFs) have been shown to allow a significant increase of the fundamental mode-field area to avoid such nonlinearities. 7 A Q-switched TDFL based on a PCF was first demonstrated by Kadwani et al in 2012.…”