1940 nm, 1966 nm and 2066 nm multi-wavelength CW and passively-Q-switched operation of L-shaped Tm³⁺:Lu₂O₃ ceramic laser in-band fiber-laser pumped at 1670 nm

Abstract

A Tm3+:Lu2O3 ceramics laser with the L-shaped cavity in-band pumped by a fiber laser at 1670 nm was studied in CW and passively Q-switched multi-wavelength regimes. The CW laser operated at 2066 nm at the weak pump power and self-tuned to 1966 nm and further to 1940 nm at higher pump power. The maximum power in the CW regime at 1940 nm reached 9.5 W, while the average power of 3.6 W was registered in the Q-switched regime with the pulse repetition rate of 110–170 kHz and the pulse duration of 200–240 ns. The Q-switched operation was obtained using a Cr2+:ZnSe saturable absorber. Pulsed regime started at the shortest wavelength of 1940 nm and self-tuned to the double-wavelength of 1940 nm and 1966 nm at higher pump power.

CW and Q-switched operations of a Tm3+:YAP laser at 1892–1994 nm In-band fiber-laser pumped at 1670 nm

“…where σ abs l is the emission cross section for a l-polarized eigenwave [17,[38][39][40][41]. To calculate the gain spectra of the Tm 3+ :YAP laser by the Expr.…”

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

“…The in-band pumping of the 3 H6-3 F4 Tm 3+ -ion transition enables the high-efficiency and high-power operation of Tm 3+ -doped lasers at 1900-2100 nm with a low quantum defect [12][13][14][15][22][23][24][25][26][27]. Direct excitation of Tm 3+ ions into the upper laser level 3 F4 results in the reduced thermal load and high laser efficiency compared to the diode pumping into 3 H4 level with the cross relaxation ( 3 H4, 3 H6) → ( 3 F4, 3 F4).…”

“…In this paper an overview of our recent achievements in the 2-μm solid-state lasers based on Tm 3+doped ceramics (Lu2O3 or Y2O3) or YAP crystals in-band pumped by a fiber laser at 1670 nm is reported [12][13][14][15]. Different operation modes (CW, actively or passively Q-switch) of our lasers are described.…”

Achievements and Future Perspectives of the Trivalent Thulium-Ion-Doped Mixed-Sesquioxide Ceramics for Laser Applications

“…Over the last several years, a large number of scientific papers focused on trivalent thulium ions (Tm 3+ ) as activators in laser-grade materials have been published, because Tm 3+ , together with Ho 3+ [ 1 ], is an excellent candidate for the development of laser sources emitting in the near- and mid-infrared, from 1.5 to 2.3 µm [ 2 ]. As a matter of fact, the most common bulk matrices (i.e., crystals and transparent polycrystalline ceramics [ 3 ])—such as YAG [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ], Lu 2 O 3 [ 12 , 13 , 14 , 15 , 16 ], Sc 2 O 3 [ 17 , 18 , 19 , 20 , 21 ], Y 2 O 3 [ 22 , 23 , 24 , 25 ], YLF [ 26 , 27 ], CaF 2 [ 28 , 29 , 30 ], LuAG [ 31 , 32 , 33 ]—were developed and studied achieving good performance in terms of laser output power, short pulse duration, and broad range of tunability (from 1.84 to 2.07 µm).…”

“…Among outstanding hosts, many research groups have focused their attention on three cubic sesquioxide ceramics [ 46 ]—i.e., Lu 2 O 3 [ 14 , 15 , 16 ], Sc 2 O 3 [ 21 ], and Y 2 O 3 [ 22 ]—because they can form solid solutions—i.e., (Lu,Sc,Y) 2 O 3 —maintaining excellent thermomechanical properties and optical quality. It is well known that sesquioxide ceramics show high thermal conductivity, a high refractive index (i.e., 1.94 at 800 nm and 1.92 at 2066 nm in 2 at.…”