Passive Q-switching of the diode pumped Tm^3+:KLu(WO_4)_2 laser near 2-µm with Cr^2+:ZnS saturable absorbers

Abstract

Single pulse energies as high as 145 µJ were generated with a passively Q-switched diode-pumped Tm:KLu(WO₄)₂ laser using poly-crystalline Cr²⁺:ZnS as a saturable absorber. The maximum average power reached 0.39 W at a pulse repetition rate of 2.7 kHz with pulse durations in the 25 - 30 ns range. The maximum peak power amounted to 6 kW. The obtained results agree well with theoretical analysis.

Passive Q-switching of a diode-pumped (Tm,Yb):KLu(WO4)2 laser near 2-μm with a Cr2+:ZnS saturable absorber

“…In this way, the higher gain values tend to indicate longer lifetime for samples (3) and (4). As in our previous work on singly doped Tm:KLuW, 14 the best transmission of the output coupler in terms of stability of the Q-switched pulses and average output power was T OC =9%. The estimated laser beam diameters were 140 and 350 µm in the position of the (Tm,Yb):KLuW crystal and the SA (placed at a distance of L SA =40 mm from the output coupler), respectively.…”

Thermal lensing and microchip laser performance of N g-cut Tm3+:KY(WO4)2 crystal

“…Efficient diode-and laser-pumped cw bulk [15][16][17], waveguide [13,18] and thindisc [19,20] Tm:KREW lasers were recently demonstrated. Tm-doped double tungstates were also utilized in laser systems with Q-switched [21][22][23] and mode-locked [24][25][26] operation modes. The power scaling capabilities for these materials are restricted by moderate value of thermal conductivity [27] and profound anisotropy of physical properties [28] which lead to complicated thermo-optic distortions pattern.…”

Tm:KLu(WO_4)_2 microchip laser Q-switched by a graphene-based saturable absorber

“…Due to the CR processes, the heat loading in Tm:DTs is relatively low [6]. Highly efficient multi-watt continuous-wave (CW) [7,8], Q-switched [9,10] and fs mode-locked [11,12] Tm:KREW lasers were realized recently.…”

“…Passive Q-switching (PQS) of diode-pumped Tm:KLuW and Tm:KYW lasers was realized with Cr 2+ -doped ZnS [9] and PbS quantum-dot-doped glass [10]. Graphene, a single atomic carbon layer [13], is emerging as ultra-broadband saturable absorber (SA) for the near-IR with beneficial properties including high optical transparency, ultrafast saturable absorption, fast recovery time and moderate modulation depth [14][15][16].…”