Multi-kW peak power acousto-optically tunable thulium-doped fiber laser system

Abstract

We demonstrate a core-pumped Q-switched thulium-doped fiber laser system with fast tunability capability over 100 nm without any movable part. With up to 7 kW peak power in a diffraction-limited beam, this source is well adapted for pumping a frequency agile mid-IR parametric oscillator or amplifier based on Quasi-Phase-Match single-period crystals.

Actively Q-switched tunable single-longitudinal-mode 2 µm Tm:YAP laser using a transversally chirped volume Bragg grating

“…However, since the obtained pulse energy and duration are already well-suited to pump both the NesCOPO and a parametric OP-GaAs amplifier, future work will mainly focus on the increase of the overall system efficiency and long-term stability while maintaining a similar working point. The 20 nm tuning range we demonstrated is smaller than what has already been demonstrated with thulium lasers [5][6][7][10][11][12]. In our case, the tuning range is restricted by the current technical limitation of the fabrication process of the TC-VBG.…”

“…In this work we obtained up to 270 µJ pulses with 50 ns pulse duration, providing 5.4 kW peak power on a single longitudinal mode. Most of the reported systems [9][10][11][12][13] present peak powers that also stand in the 1 to 10 kW range but are multi-longitudinal-mode. Reference [7,8,14,15] present much higher peak powers ranging from 20 to 160 kW, but, either they are multi-longitudinal-mode, or they use a much more complex laser design.…”

“…Thulium doped [11,12] or thulium, holmium co-doped [13] fiber lasers exhibit high repetition rate from several tens of kHz [11,12] to several hundred of kHz [13] using acousto-optic modulators, and near diffraction limited beams. A tunability of 100 nm with a linewidth of 0.8 nm using an acousto-optic tunable filter has been demonstrated [11] while a larger tunability of 180 nm and a narrower linewidth of 0.2 nm were achieved using a diffraction grating as of the end cavity mirror [12,13]. However, these lasers are rather complex due to the combination of free space optical components and a fiber gain medium.…”

A narrowband infrared source based on orientation-patterned GaAs for standoff detection of chemicals

“…Increasing the tunability range of the NesCOPO can readily be done by adding more QPM tracks in the crystal. The NesCOPO tunability could also be increased or made faster by tuning the pump wavelength directly, which is made possible thanks to the latest 2 μm source developments [68]. In an optical parametric amplifier based on QPM crystals, the tunability can be increased in the same way as in an optical parametric oscillator.…”

Focus issue introduction: Advanced Solid-State Lasers (ASSL) 2016

“…Gutty et al [11] demonstrated a core-pumped Q-switched thulium-doped fiber laser system with fast tuning capability over 100 nm without any movable part. With up to 7 kW peak power in a diffraction-limited beam, this source is well adapted for pumping a frequency agile mid-IR parametric oscillator or amplifier based on quasi-phase-matched single-period crystals.…”