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1.
A. Agnesi S. Dell’Acqua A. Guandalini G. Reali A. Toncelli M. Tonelli E. Cavalli 《Applied physics. B, Lasers and optics》2000,71(2):153-156
CW diode-pumped laser operation of Nd3+ in Ca3Sc2Ge3O12 (CaSGG) single garnet crystal has been demonstrated for the first time. We measured an 18% slope efficiency and 2.7-nm tunability
with two different laser cavities. A spectroscopic characterization of our sample has also been performed including the absorption
cross section in the 800-nm region and the emission cross section and radiative lifetime of the upper laser level.
Received: 7 December 1999 / Revised version: 6 February 2000 / Published online: 27 April 2000 相似文献
2.
Dynamics of the Yb3+ to Er3+ energy transfer in LiNbO3 总被引:1,自引:0,他引:1
The energy transfer dynamics between Yb3+ and Er3+ ions in lithium niobate is investigated after ytterbium-pulsed excitation at 920 nm. The sensitisation of the LiNbO3:Er3+ system with Yb3+ ions does not modify the lifetime of the 4I13/2 erbium level (1.5-μm emission), whereas it induces a marked, concentration-dependent change in the lifetime of the 2F5/2 (Yb3+) and 4S3/2 (Er3+) multiplets (1060-nm and 550-nm emissions, respectively). The results are analysed by using the rate-equation formalism and
cross-relaxation model for the energy transfer.
Received: 15 October 1998 / Revised version: 24 November 1998 / Published online: 24 February 1999 相似文献
3.
Spectroscopic characterization of a Tm3+:SrGdGa3O7 crystal 总被引:2,自引:0,他引:2
W. Ryba-Romanowski S. Gołvab I. Sokólska G. Dominiak-Dzik J. Zawadzka M. Berkowski J. Fink-Finowicki M. Baba 《Applied physics. B, Lasers and optics》1999,68(2):199-205
3 O7 crystal have been recorded at room temperature and at approximately 8 K. Room-temperature luminescence lifetimes of 1D2, 1G4, 3H4, and 3F4 states have been measured for Tm concentration ranging from [%at.]0.5 to [%at.]9. Based upon these data the crystal field
splitting of luminescent states has been derived and radiative transitions rates have been evaluated. Strong self-quenching
of luminescence originating in the 1G4 and 3H4 states has been found in this activator–host combination. Peak emission cross section of the potential laser transition at
1800 nm was determined to be 3.9×10-21 cm2 and the gain coefficient versus wavelength was estimated and discussed.
Received: 14 April 1998/Revised version: 10 August 1998 相似文献
4.
W. Ryba-Romanowski M. Berkowski B. Viana P. Aschehoug 《Applied physics. B, Lasers and optics》1997,64(5):525-529
3 H4 and 3F4 states of Tm in SrGdGa3O7 single crystal was evaluated. Tm-Tb energy transfer reduces effectively the lifetime of terminal level in a potential 3H4-3F4 laser transition but gives rise to parasitic nonradiative relaxation of the initial 3H4 level. SrGdGa3O7 crystal single doped with thulium possesses combination of properties advantageous for laser oscillations near 1.9 μm, namely
high rate of cross relaxation process leading to population buildup on the initial 3F4 level and relatively high crystal field splitting of the ground 3H6 level.
Received: 25 April 1996/Revised version: 10 October 1996 相似文献
5.
I. Sokólska 《Applied physics. B, Lasers and optics》2000,71(2):157-162
LaGaO3 crystals doped with Er3+ ions were grown by the Czochralski method and their optical properties were examined. The Er3+ energy levels have been determined from the low-temperature absorption and emission spectra. The results of Judd–Ofelt analysis
are presented and compared with experimental data. The emission cross sections are determined for the 4
I
13/2→4
I
15/2 (1.55 μm) and 4
I
11/2→4
I
13/2 (2.85 μm) transitions of erbium.
Received: 6 December 1999 / Revised version: 10 February 2000 / Published online: 27 April 2000 相似文献
6.
W. Ryba-Romanowski A. Brenier C. Garapon A. Gloubokov 《Applied physics. B, Lasers and optics》1995,61(4):345-350
Single crystals of SrLaAlO4: Pr3+ and SrLaAlO4: Nd3+ have been grown by the Czochralski method and their optical properties have been studied for different activator concentrations. The absorption and emission spectra of the activators are inhomogeneously broadened because the Sr2+ and La3+ ions are distributed randomly on the sites ofC
4
symmetry, however, the symmetry selection rules are still obeyed. Strong self-quenching of the praseodymium luminescence occurs by cross relaxation which is supposed to be assisted by phonon emission in the case of the3
P
0 level. Self-quenching of Nd3+ luminescence disappears at low temperature indicating that the condition of resonance in the cross-relaxation process is fulfilled only for higher components of the ground state.Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wroclaw, Poland 相似文献
7.
The optical properties of Yb3+ ions in LiTaO3:Nd,Yb crystals 总被引:1,自引:0,他引:1
I. Sokólska W. Ryba-Romanowski S. Gołab T. Lukasiewicz 《Applied physics. B, Lasers and optics》1997,65(4-5):495-498
3+ ions excited by energy transfer from Nd3+ ions in LiTaO3:Nd, Yb crystals are presented. The emission band of Yb3+ ions is broad, due to the strong phonon-coupling and to the relative large Stark-splitting of the ground 2F7/2 multiplet. The emission cross-section was evaluated by the reciprocity method, and a value of 0.53×10-20 cm2 was obtained. The gain coefficients derived for the inversion parameters in the range 0.05 to 0.5 indicate positive gain
in the 985–1070 nm range.
Received: 17 March 1997/Revised version: 10 June 1997 相似文献
8.
V. Lupei A. Lupei N. Pavel T. Taira A. Ikesue 《Applied physics. B, Lasers and optics》2001,73(7):757-762
A high-resolution spectroscopic and emission-decay investigation of highly concentrated Nd:YAG single crystals and ceramics
shows that the state of the Nd3+ ions and their interaction in these materials are similar and can be used for construction of efficient solid-state lasers
directly pumped in the emitting level. This possibility is demonstrated by continuous-wave emission of concentrated Nd:YAG
crystals with up to 3.5 at. % Nd and ceramics with up to 6.8 at. % Nd under resonant 885-nm end pump.
Received: 28 May 2001 / Final version: 17 August 2001 / Published online: 10 October 2001 相似文献
9.
F. Mougel F. Augé G. Aka A. Kahn-Harari D. Vivien F. Balembois P. Georges A. Brun 《Applied physics. B, Lasers and optics》1998,67(5):533-535
3+ :Ca4GdO(BO3)3 (Nd:GdCOB). 21 mW of green cw laser emission for an absorbed pump power of 820 mW were achieved under laser diode-pumping.
64 mW of green cw laser output were obtained with 1 W of absorbed pump power under titanium-sapphire pumping. Its availability
in large-size crystals with good optical quality makes Nd:GdCOB a true challenger to the best SFD laser crystal reported so
far: Nd:YAl3(BO3)4 (Nd:YAB or NYAB).
Received: 2 March 1998/Revised version: 20 May 1998 相似文献
10.
Crystalline structure and optical spectroscopy of Er3+-doped KGd(WO4)2 single crystals 总被引:2,自引:0,他引:2
M.C. Pujol M. Rico C. Zaldo R. Solé V. Nikolov X. Solans M. Aguiló F. Díaz 《Applied physics. B, Lasers and optics》1999,68(2):187-197
4 )2 single crystals doped with Er3+ have been grown by the flux top-seeded-solution growth method. The crystallographic structure of the lattice has been refined,
being the lattice constants a=10.652(4), b=10.374(6), c=7.582(2) Å, β=130.80(2)°. The refractive index dispersion of the host
has been measured in the 350–1500 nm range. The optical absorption and photoluminescence properties of Er3+ have been characterised in the 5–300 K temperature range. At 5 K, the absorption and emission bands show the (2J+1)/2 multiplet
splittings expected for the C2 symmetry site of Er in the Gd site. The energy positions and halfwidths of the 72 sublevels observed have been tabulated
as well as the cross sections of the different multiplets. Six emission band sets have been observed under excitation of the
4F7/2 multiplet. The Judd–Ofelt (JO) parameters of Er3+ in KGW have been calculated: Ω2=8.90×10-20 cm2, Ω4=0.96×10-20 cm2, Ω6=0.82×10-20 cm2. Lifetimes of the 4S3/2, 4F9/2, and 4I11/2 multiplets have been measured in the 5–300 K range of temperature and compared with those calculated from the JO theory.
A reduction of the 4S3/2 and 4I11/2 measured lifetimes with increasing erbium concentration has been observed, moreover the presence of multiphonon non-radiative
processes is inferred from the temperature dependence of the lifetimes.
Received: 15 December 1997/Revised version: 10 July 1998 相似文献
11.
G. Dominiak-Dzik S. Gołąb I. Pracka W. Ryba-Romanowski 《Applied Physics A: Materials Science & Processing》1994,58(6):551-555
Nonequivalent Er3+ sites in LiNbO3 crystals have been evidenced by low-temperature optical absorption measurements. The radiative transition rates for the 4
S
3/2, 4
F
9/2, 4
I
9/2, 4
I
11/2, and 4
I
13/2 levels have been evaluated by the Judd-Ofelt method, and the contribution of multiphonon relaxation to the decay of excited states has been estimated. The quantum efficiency of the 4
I
11/2 level has been estimated to be 6% only, thus the excitation of levels lower than 4
S
3/2 is expected to populate efficiently the 4
I
13/2 level. 相似文献
12.
Continuous-wave tunable Cr2+:ZnS laser 总被引:1,自引:0,他引:1
I.T. Sorokina E. Sorokin S. Mirov V. Fedorov V. Badikov V. Panyutin A. Di Lieto M. Tonelli 《Applied physics. B, Lasers and optics》2002,74(6):607-611
We report the first continuous-wave tunable over ∼280 nm around 2.3 μm room-temperature operation of a chemical vapor transport-grown
and diffusion-doped Cr2+:ZnS laser, pumped by a Co:MgF2 laser at 1.67 μm and generating over 100 mW of output power at 16% slope efficiency. The self-consistent results of the laser
and spectroscopic analysis demonstrate a large potential of this crystal as an active medium for diode-pumped tunable mid-infrared
sources.
Received: 7 January 2002 / Revised: 14 March 2002 / Published online: 2 May 2002 相似文献
13.
A.V. Podlipensky V.G. Shcherbitsky N.V. Kuleshov V.I. Levchenko V.N. Yakimovich M. Mond E. Heumann G. Huber H. Kretschmann S. Kück 《Applied physics. B, Lasers and optics》2001,72(2):253-255
Efficient continuous-wave laser operation of Cr2+:ZnSe was demonstrated with an output power of 1400 mW at an absorbed pump power of 1900 mW from a Tm:YAG laser. Under continuous-wave
diode pumping at 1.54 μm an output power of 15 mW was obtained from a Cr+2:ZnSe laser. Excited state absorption is shown to be negligible in the pump and laser spectral region.
Received: 12 October 2000 / Published online: 30 November 2000 相似文献
14.
W. Ryba-Romanowski S. Gołvab G. Dominiak-Dzik P. Solarz 《Applied Physics A: Materials Science & Processing》2002,74(4):581-586
Polycrystalline samples of europium-doped K5Li2GdF10 have been obtained by a slow cooling of melted compound and investigated using spectroscopy methods. Luminescence from the
5
D
2 level of Eu3+ is found to be weak. Intense visible emission upon excitation into the 5
D
2 or higher energy levels has been attributed to overlapping transitions from long-lived 5
D
1 and 5
D
0 levels. A strong increase of the 5
D
0 emission at the expense of the 5
D
1 emission occurs between 5 K and 25 K without significant change of the 5
D
1 lifetime. To account for this, it is supposed that both the radiative and the nonradiative transition rates are temperature-dependent.
Efficient energy transfer from the 6
G
J levels of Gd3+ to Eu3+ ions has been evidenced by excitation spectra in the VUV region and VUV-excited luminescence. It has been concluded that
the cross relaxation contributes to the energy-transfer process.
Received: 8 May 2001 / Accepted: 11 May 2001 / Published online: 25 July 2001 相似文献
15.
J. Lu M. Prabhu J. Song C. Li J. Xu K. Ueda A.A. Kaminskii H. Yagi T. Yanagitani 《Applied physics. B, Lasers and optics》2000,71(4):469-473
Optical absorption, emission spectra have been measured for polycrystalline Nd-doped Y3Al5O12 ceramics. Fluorescence lifetimes of 257.6 μs, 237.6 μs, 184.2 μs and 95.6 μs have been obtained for 0.6%, 1%, 2% and 4% neodymium-doped
YAG ceramics, respectively. For the first time, highly efficient laser oscillation at 1064 nm has been obtained with this
kind of ceramics. Slope efficiency of 53% has been achieved on a uncoated 4.8-mm thick 1% Nd:YAG ceramics sample. Optical
to optical conversion efficiency is 47.6%. Laser oscillation has also been obtained with a 2% Nd:YAG ceramics. The optical
properties and laser output results have been compared with that of Nd:YAG single crystal grown by the Czochralski method.
Almost identical results have been achieved including laser experiments results. But fabrication of Nd:YAG ceramics is much
easier compared to the single-crystal growth method. And also large size (now of about 400 mm diameter×5 mm is available)
and high-concentration (>1%) Nd:YAG ceramics can be fabricated. The results show that this kind of Nd:YAG ceramics is a very
good alternative to Nd:YAG single crystal.
Received: 20 April 2000 / Published online: 16 August 2000 相似文献
16.
Random laser action in ZnO 总被引:1,自引:0,他引:1
We report a direct evidence of random laser in optically pumped ZnO powder. Discrete lasing modes are observed above threshold.
The laser emission spectra depend on the angle of observation and are random. The lasing action is attributed to the coherent
feedback due to recurrent light scattering in the powder. The lasing threshold intensity depends on the excitation volume.
Received: 15 September 1999 / Revised version: 2 February 2000 / Published online: 5 July 2000 相似文献
17.
The absorption spectra, fluorescence spectrum and fluorescence decay curve of Nd3+ ions in CaNb2O6 crystal were measured at room temperature. The peak absorption cross section was calculated to be 6.202×10−20 cm2 with a broad FWHM of 7 nm at 808 nm for E//a light polarization. The spectroscopic parameters of Nd3+ ions in CaNb2O6 crystal have been investigated based on Judd-Ofelt theory. The parameters of the line strengths Ω
t
are Ω
2=5.321×10−20 cm2,Ω
4=1.734×10−20 cm2,Ω
6=2.889×10−20 cm2. The radiative lifetime, the fluorescence lifetime and the quantum efficiency are 167 μs, 152 μs and 91%, respectively. The fluorescence branch ratios are calculated to be β
1=36.03%,β
2=52.29%,β
3=11.15%,β
4=0.533%. The emission cross section at 1062 nm is 9.87×10−20 cm2. 相似文献
18.
Pumping with infrared light resonant to the energy position of 4
I
11/2 and 4
I
9/2 multiplets respectively has excited green up-conversion of Er3+ in KGd(WO4)2 single crystal. At room temperature the maximum green-emission intensity is achieved by pumping with light polarized parallel
to the C2 symmetry axis of the crystal (//p) at 981 and 801.5 nm, while pumping with light parallel to the principal m axis (//m) has
maximum up-conversion at 978.2, 806 and 800 nm. The emission is weakly polarized. The maximum of the emission peaks at 547.8 nm
if the light is analyzed parallel to the C2 axis or at 552.4 nm for light perpendicular to it. The largest emission intensity was achieved with an erbium concentration
about 3×1020 cm-3. A schematic model of the up-conversion process is suggested.
Received: 4 July 2000 / Published online: 22 November 2000 相似文献
19.
We report on the frequency doubling of Q-switchedNd:YAG and Nd:YAlO3 lasers emitting at 946 and 930 nm, respectively (4F3/2 to 4I9/2 transition). The neodymium-doped laser host crystals were excited with a flashlamp-pumped Cr:LiSAF laser operating in a free-running
mode. Blue-light pulses were obtained at both 473 nm (9 mJ, 25 ns FWHM) and 465 nm (4.4 mJ, 35 ns FWHM) by using a potassium
niobate crystal as an extra-cavity frequency doubler. The second-harmonic generation conversion efficiencies reached 53% and
31%, respectively.
Received: 23 June 1999 / Revised version: 8 August 1999 / Published online: 3 November 1999 相似文献
20.
V.G. Gudelev V.V. Mashko N.K. Nikeenko G.I. Ryabtsev A.B. Stalmashonak L.L. Teplyashin 《Applied physics. B, Lasers and optics》2003,76(3):249-252
Using the mode splitting that can be achieved by exploiting the effect of photoelasticity and the mode selection properties
of coupled resonators, single- and two-frequency operation of a diode pumped cw YAG:Nd3+ laser was observed. In the two-frequency case, a regime with two orthogonal linearly polarized modes was realized. The frequency
difference between the adjacent modes could be varied from 50 MHz to 8.4 GHz. A maximum laser output power of 12 mW was achieved
at a pump level of 240 mW .
Received: 1 November 2002 / Revised version: 14 January 2003 / Published online: 19 March 2003
RID="*"
ID="*"Corresponding author. Fax: +375-17/2840-879, E-mail: ryabtsev@dragon.bas-net.by 相似文献