Efficient 2.1‐μm lasers based on Tm^3+:Lu₂O₃ ceramics pumped by 800–nm laser diodes

Abstract

Structural, optical and spectroscopic properties of Tm3+:Lu2O3 ceramics were studied. CW laser operation at 2068 nm with an output power of up to 34 W and a slope efficiency of 44% was obtained. Q‐switched ocsilation with a pulse duration of 100‐150 ns and a repetition rate of 1‐10 kHz was achieved. Passive mode locking was achieved using an ion‐implanted InGaAsSb quantum‐well based SESAM or single graphene layer. Transform‐limited pulses as short as 180 fs are generated at 2076 nm with an average output power of 400 mW and a pulse repetition frequency of 121.2 MHz. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

High efficiency in-band pumped Tm- and Ho-doped 2-μm solid-state lasers

“…The Tm 3+ ions have a number absorption bands in near-IR wavelength region and can be pumped at ~800 nm (the 3 H6 -3 H4 transition band), ~1200 nm (the 3 H6 -3 H5 transition band) or ~1700 nm (the 3 H6 -3 F4 transition band) for 1800-2300 nm lasing (Figure 1) [1][2][3][4]10]. the absorption cross section of Tm 3+ :Lu2O3 ceramics (c) [18].…”

“…The mature high power laser diodes around 800 nm can be used as the pump sources via the 3 H6→ 3 H4 transition with the subsequent cross relaxation ( 3 H4, 3 H6) → ( 3 F4, 3 F4) of the Tm 3+ ions with the phonon assistance. This pumping scheme has been realized for different Tm 3+ -doped laser crystals and ceramics [1,10,18,19]. The optically-pumped semiconductor laser at 1200 nm provided the 3 H6→ 3 H4 transition was also used for the Tm 3+ -doped ceramics pumping [20].…”

“…CW and Q-switched laser operations of in-band pumped Tm 3+ :Lu2O3 and Tm 3+ :Y2O3 ceramics 3.1. Multi-wavelength operation of in-band pumped Tm 3+ :Lu2O3 ceramic lasers at 2068 nm, 1968 nm and 1940 nm High-efficiency and high average power laser operations in CW and actively Q-switched regimes were previously demonstrated at 2 µm in Tm 3+ :Lu2O3 ceramics using diode pumping at 796 nm or fiber laser pumping at 1200 nm and 1670 nm [18,20,36,37]. A double-wavelength operation at 2066 nm and 1967 nm of the linear-cavity Tm 3+ :Lu2O3 ceramics lasers in-band pumped at 1670 nm was demonstrated in [18].…”

“…Multi-wavelength operation of in-band pumped Tm 3+ :Lu2O3 ceramic lasers at 2068 nm, 1968 nm and 1940 nm High-efficiency and high average power laser operations in CW and actively Q-switched regimes were previously demonstrated at 2 µm in Tm 3+ :Lu2O3 ceramics using diode pumping at 796 nm or fiber laser pumping at 1200 nm and 1670 nm [18,20,36,37]. A double-wavelength operation at 2066 nm and 1967 nm of the linear-cavity Tm 3+ :Lu2O3 ceramics lasers in-band pumped at 1670 nm was demonstrated in [18]. An efficient booster amplifier for a pulsed fiber laser at 1940 nm based on Tm 3+ :Lu2O3 ceramics with fiber-laser pumping at 1670 nm was also reported in [25].…”

“…Figure 1. The energy level diagram of Tm 3+ ions in a Tm 3+ :Y2O3 ceramics with the absorption and emission transitions in different colours (a) [16]; the absorption (blue) and emission (red) cross-sections of Tm 3+ :Y2O3 ceramics for the transition term of 3 H6-3 F4 [17] (the vertical arrows indicate the pumping at 1670 nm (blue) or 796 nm (violet), the laser operation wavelength of 2050 nm (red), and the cross-relaxation process (green)) (b);the absorption cross section of Tm 3+ :Lu2O3 ceramics (c)[18].…”