Thin disk Tm-laser based on highly doped Tm:KLu(WO4)2/KLu(WO4)2 epitaxy

Abstract

Continuous-wave (CW) Tm-laser operation is achieved for the first time using the thin disk laser concept and an epitaxial active element based on the monoclinic KLu(WO 4 ) 2 crystal with 15 at.% thulium doping of the overgrown layer, which is only 80 μm thick. A single double pass of the pump radiation from the diode-laser ensures efficient pumping due to the large absorption of the active layer. For output coupling between 0.4% and 2.8%, the slope efficiency in the CW regime is in the 7 -11% range and the laser threshold amounts to 1.5 -2.5 W of absorbed pump power. The laser emission spectra are centered at ∼ 1850, 1915, and 1940 nm for output couplers of 2.8%, 1.6%, and 0.4% transmission, respectively. In all cases the emission spectra are "structured", consisting of a number (typically 5-10) of narrow emission lines spread irregularly over 15 -30 nm. Physical cavity length, mm Average output power of the epitaxial Tm:KLuW/KLuW(010) laser in the QCW regime versus physical cavity length. The incident average pump power is 2.8 W, the output coupler transmission is T = 1.6%, and the duty cycle is 18%

High-efficiency lasing and spectroscopy of domestic 1%Nd:YAG and 1%Ho:YAG ceramics

“…Hence, relations (1) and (2) give a possibility to estimate the parameter T loss which is ~1.2% at η = 45%; this is in good agreement with results from [17,18]. The estimate T loss ~ 1.2 % also seems reasonable taking into account a large number of optical surfaces inside the cavity.…”

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.…”

Diode-pumped Q-switched Tm:LuAG ring laser operation at room temperature

“…Compared with the crystal YAG, LuAG has a higher crystal field, leading to large man ifold splitting and low thermal occupation for the lower laser level. In experiment, Tm, Ho doped LuAG laser has achieved higher laser efficiency at 2 µm than the YAG or YLF laser [8][9][10][11][12]. Scholle et al reported a SLM Tm:LuAG laser by using a etalon at room tem perature and the maximal output power was 51 mW [13].…”