55 W actively Q-switched single oscillator Tm³⁺, Ho³⁺-codoped silica polarization maintaining 209 µm fiber laser

Abstract

A bidirectional 793 nm diode-pumped actively Q-switched Tm 3+ , Ho 3+-codoped silica polarization-maintaining (PM) double-clad (DC) fiber laser is reported. With this fiber laser, 55 W of average output power with 100 ns pulse width at 200 kHz repetition rate and 2.09 µm wavelength is obtained. The pump power injection with end-caps fusion-spliced on fiber tips provides good power stability (< 1.1%) and beam quality factors (M 2 < 1.7). The fiber laser output beam polarization factor is 97.5%. At 55 W, no thermal-induced damage is observed on any optical element, and power scaling of the laser is only pump-power-limited in the range of the total available pump power (180 W).

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

“…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.…”

“…A Q-switched Tm:LiLuF 4 laser passively Q-switched by a Cr:ZnS saturable absorber with 26.2% slope efficiency at a 1.33 kHz repetition rate with 340 µJ and 51.6 ns pulses tunable from 1914.1 to 1965.2 nm was demonstrated by Yu et al [10]. 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].…”

High-efficiency continuous-wave Tm-doped fiber laser with a single fiber Bragg grating at 1942 nm

“…The operating wavelength of a Tm-doped fiber (TDF) laser is in the eye-safe region [1], and there is good absorption by CO 2 and H 2 O [2]. TDFs are attractive for many applications including biotechnology [3], plastic welding [4] and optical countermeasures [5] and are an ideal pumping source at 3-5 µm [6]. In 2010, O-Peak reported the first continuouswave laser of more than 1 kW at 2045 nm peak wavelength [7].…”

2.1 m, high-energy dissipative soliton resonance from a holmium-doped fiber laser system

“…For example, a 2.108 μm high-energy nanosecond pulse from an all-fiber holmium-doped amplification system has been applied in ZGP-OPO and obtained a mid-infrared conversion efficiency of up to 59% [ 7 ] . By employing thulium-doped fiber (TDF) [ 10 , 11 ] , thulium-holmium co-doped fiber (THDF) [ 12 ] , holmium-doped fiber (HDF) [ 13 , 14 ] , pulsed laser at wavelengths exceeding 2 μm have been achieved. Compared with TDF and THDF, HDF pumped by a 1950 nm laser has higher lasing efficiency, especially in the emission range of 2050–2150 nm [ 15 ] .…”