Lasing in diode-pumped thulium and thulium, holmium YAP (original) (raw)
Related papers
Journal of Luminescence
We present detailed measurements of laser relevant cross sections of thulium doped yttrium-aluminum-garnet (Tm:YAG) and yttrium-aluminum-perovskite (Tm:YAP), including the absorption cross sections for the H 6 3 to H 4 3 transition near 800 nm, and the absorption and emission cross sections for the transitions between the H 6 3 and F 4 3 manifolds in the short-wavelength infrared region. For Tm:YAP we present data for all polarization axes. The measurements were carried out at temperatures ranging from 80 K to 300 K. Furthermore, re-absorption free fluorescence lifetimes of the F 4 3 to H 6 3 transition at 77 K, 200 K and 295 K were obtained using the pinhole method. We observed a significant enhancement of the fluorescence lifetime when cooling from room temperature to 77 K. The lifetime was increased from 9.42 ms to 15.22 ms in Tm:YAG and from 3.81 ms to 4.93 ms in Tm:YAP. This indicates that lifetime quenching is present at room temperature, which can be overcome, at least partially, by cryogenic cooling. These data are presented with the scope to qualify these materials for their use in a new generation of cryogenically cooled, short-wavelength infrared, high-energy class diode pumped solid state lasers utilizing the cross relaxation mechanism for pumping.
Novel ytterbium and thulium lasers based on the monoclinic KLu(WO 4)2 crystalline host
2007
High-quality crystals of KLu(WO 4) 2 , shortly KLuW, were grown with sizes sufficient for characterization of the thermomechanical and optical properties, and substantial progress was achieved in the field of spectroscopy and laser operation with Yb 3+-and Tm 3+-doping. We review the properties of flux grown KLuW, the Yb 3+ and Tm 3+ spectroscopy, and present laser results obtained in several operational regimes both with Ti:sapphire and direct diode laser pumping using InGaAs and AlGaAs diodes near 980 and 800 nm, respectively. The slope efficiencies with respect to the absorbed pump power achieved with continuous-wave (CW) bulk and epitaxial Yb:KLuW lasers under Ti:sapphire laser pumping were ≈57 and ≈66%, respectively. Output powers as high as 3.28 W were obtained with diode pumping in a simple two-mirror cavity where the slope efficiency with respect to the incident pump power reached ≈78%. Passively Q-switched laser operation of bulk Yb:KLuW was realized with a Cr:YAG saturable absorber resulting in oscillation at ≈1031 nm with a repetition rate of 28 kHz and simultaneous Raman conversion to ≈1138 nm with maximum energies of 32.4 and 14.4 µJ, respectively. The corresponding pulse durations were 1.41 and 0.71 ns. Passive mode-locking by a semiconductor saturable absorber mirror (SESAM) resulted in bandwidth-limited pulses with duration of 81 fs (1046 nm, 95 MHz) and 114 fs (1030 nm, 101 MHz) for bulk and epitaxial Yb:KLuW lasers, respectively. Slope efficiency as high as 69% with respect to the absorbed power and an output power of 4 W at 1950 nm were achieved with a diode-pumped Tm:KLuW laser. The tunability of this laser, under Ti:sapphire laser pumping, extended from 1800 to 1987 nm. An epitaxial Tm:KLuW laser provided slope efficiency as high as 64% and a tuning range from 1894 to 2039 nm when pumped by a Ti:sapphire laser.
Lasing in diode-pumped Tm:YAP, Tm,Ho:YAP and Tm,Ho:YLF
Optics Communications, 1998
A comparison of the room-temperature operation of continuous wave Tm:YAP, Tm,Ho:YAP and Tm,Ho:YLF lasers is reported. A conversion efficiency from absorbed pump power to laser output of 42% was demonstrated in Tm:YAP, compared to 14% in Tm,Ho:YAP and 30% in Tm,Ho:YLF. Tm:YAP was observed to operate multiline in the range 1.965 to 2.020 mm, whereas the holmium lasers operated on a single transition. The markedly different temporal behaviour of the single and double-doped crystals is analysed and discussed. q 1998 Elsevier Science B.V.
High Energy Crystalline Laser Materials
A potential high energy laser material, GdAlO» doped with chromium, is discussed in terms of its growth problems and spectroscopic characteristics. Crystals have been pulled frotr the melt, but difficulties in maintaining stolchiometry during growth have not been completely solved. The fluorescence of Cr lias an 18 nsec decay time and a broad R-llne. The width and structure of the R-llnes are theoretically described as due to the ferromagmjtic exchcnge inter-3+ actions with neighboring Gd ions. , 1 i OBJECTIVES ij ~t To Investigate crystals which show potential as high power J laser materials, the study to include both spectroscopic measurements Pj and the development of crystal growth techniques. The ultimate objective is to discover a laser crystal that is capable of a greater total output energy in a Q-spoiled laser mode than presently available If materials. Summary The study has concentrated on oxide crystals doped with chromium in which the chromium R-line fluorescence has a long decay time and/or a broad line width so that laser gain will be sufficiently low to prevent saturation due to amplified spontaneous emission. Crystalline materials that meet these requirements are lanthanum aluminate (LaAlO.), gadolinium aluminate (GdAlO.), and magnesium aluminum spinel (MgAl_0.), all doped with chromium. The studies on these materials showed that LaA10.:Cr has sharp emission lines having a 76 ms lifetime (77 <> K), GdAlO :Cr has broad lines (^ 50A) having an 18 ms lifetime, and MgAl_0.;Cr has broad lines (^ 80A) having a 12 ms lifetime. Crystal growth of LaAlO did not result in good quality crystals due to a phase transition at 425 0 C which causes domains to form, although work by another contractor showed that it may be possible to improve the quality of these crystals after growth by applying uniaxial pressure. No phase transition occurs in GdA10" but the results of Czochralski growth have not been completely*satisfactory, possibly because of the purity of the starting materials. Work on MgAl-O. growth has been pursued by another contractor. 17 *■ li \ band. The peak energies are listed in Table I.
Spectroscopic investigations of the new active media for diode-pumped solid-state lasers
1995
Investigation of spectroscopic properties of yttrium-aluminum garnet Y3Al5O12 (YAG) doped with ions of rare-earth elements Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Ho3+, Er3+, Tm3+, Yb3+ monocrystals yttrium-aluminum perovskite YAlO3 (YAP), SrLaGa3O7 (SLGO) and SrLaAlO4 (SLAO) doped with Nd3+, and LiNbO3 doped with Er3+ and Tm3+ obtained by the Czochralski method have been realized. Absorption spectra of the monocrystals were determined in
Spectroscopy, modelling and laser operation of holmium doped laser crystals
Le Journal de Physique IV, 1994
Spectroscopic studies using laser induced fluorescence and numerical modelling of energy transfer and back transfer mechanism are reported in Er:Tm:Ho:YLF, Cr:Tm:Ho:YAG and Cr:Tm:YAG laser crystals at various temperatures (10 K-300 K). Direct energy transfer from ~m~+ excited states to H O~+ ' I~ emitting level was observed and analyzed both in YAG and YLF. Further analysis of cr3+ and ~m 3 + time dependent emission curves indicate strong correlation of chromium-thulium pairs. Pulsed operation of holmium laser at high temperature will be presented.
Spectroscopic investigations of new active media for diode-pumped solid state lasers
ROMOPTO '94: Fourth Conference in Optics, 1995
Investigations of spectroscopic properties of yttrium-aluminum garnet Y 3 Al 5 O 12 (YAG) doped with ions of rare-earth elements Ce 3+ , Pr 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ monocrystals yttrium-aluminium perovskite YAlO 3 (YAP), SrLaGa 3 O 7 (SLGO) and :SrLaAlO 4 (SLAO) doped with Nd 3+ , and LiNbO 3 doped with Er 3+ and Tm 3+ obtained by the Czochralski method have been realized.
Laser & Photonics Reviews, 2007
High‐quality crystals of monoclinic KLu(WO4)2, shortly KLuW, were grown with sizes sufficient for its characterization and substantial progress was achieved in the field of spectroscopy and laser operation with Yb3+‐ and Tm3+‐doping. We review the growth methodology for bulk KLuW and epitaxial layers, its structural, thermo‐mechanical, and optical properties, the Yb3+ and Tm3+ spectroscopy, and present laser results obtained in several operational regimes both with Ti:sapphire and direct diode laser pumping using InGaAs and AlGaAs diodes near 980 and 800 nm, respectively. The slope efficiencies with respect to the absorbed pump power achieved with continuous‐wave (CW) bulk and epitaxial Yb:KLuW lasers under Ti:sapphire laser pumping were ≈ 57 and ≈ 66%, respectively. Output powers as high as 3.28 W were obtained with diode pumping in a simple two‐mirror cavity where the slope efficiency with respect to the incident pump power reached ≈ 78%. Passively Q‐switched laser operation of bu...