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1.
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
2.
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
3.
E. Cavalli E. Zannoni A. Belletti V. Carozzo A. Toncelli M. Tonelli M. Bettinelli 《Applied physics. B, Lasers and optics》1999,68(4):677-681
3 Sc2Ge3O12 (CaSGG) single crystals with the garnet structure have been grown by means of the flux growth technique. The doping with
Nd3+ and Mg2+ (as charge compensator) yields samples suitable for optical spectroscopy experiments. The absorption and emission properties
have been measured at temperatures ranging from 10 to 298 K. The emission spectra give evidence of the presence of non-equivalent
Nd3+ sites. The decay time of the 1.06-μm emission band has been measured as a function of temperature and incident power. The
intensities of the 298 K absorption transitions have been analyzed by means of the Judd–Ofelt theory. The radiative lifetimes,
the branching ratios (β), and the spontaneous emission probabilities have been evaluated for the 4F3/2 excited state using the calculated intensity parameters. The stimulated-emission cross sections and the branching ratios
have been estimated from the experimental data for the most important laser transitions indicating that this crystal can be
considered an interesting material for solid-state laser applications.
Received: 2 June 1998 / Revised version: 28 October 1998 / Published online: 24 February 1999 相似文献
4.
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
5.
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
6.
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
7.
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
8.
S. Kück 《Applied physics. B, Lasers and optics》2001,72(5):515-562
In this work an overview of transition metal (TM) ion- and rare earth (RE) ion-doped crystals for application as tunable solid-state
lasers will be given. Spectroscopic and laser results will be presented including recent research and advances in this field.
Within this work tunability is defined as the possibility to achieve laser oscillation in the vibronic sideband of a transition.
Tunable solid-state lasers are of interest for a wide field of applications, e.g. in scientific research, in medicine, for
measurement and testing techniques, ultra short pulse generation, and communication. They can also be used as coherent light
sources for second-harmonic generation, for optical parametric oscillators, and for sum- and difference-frequency generation.
Tunable laser media based on 3d?3d transitions of transition-metal ions and 4f?5d transitions of rare-earth ions cover nowadays
almost the whole spectral range between 270 nm and 4500 nm, see Fig. 1 [1-15].
In comparison to laser systems based on the 4f?4f transitions of trivalent rare-earth ions, tunable lasers based on 3d?3d
and 4f?5d transitions are in general affected by a higher probability of excited-state absorption (ESA), a higher probability
of non-radiative decay, and a higher saturation intensity leading to higher laser thresholds. Often laser oscillation cannot
be obtained at all. These general topics will be considered in Sect. 1, where the basic aspects of tunable solid-state lasers
are discussed: these are the preparational, the spectroscopic, and the laser aspect. In Sect. 2, the investigation of transition
metal ion-doped crystals with respect to the realization of tunable laser oscillation is presented. The work is focused on
transition-metal ions of the 3d row (Fe row) and divided into two subsections according to the octahedral and tetrahedral
coordinations of the ion investigated. Each subsection is structured according to the electron configurations: 3d1, 3d3, 3d4, and 3d8 for the octahedrally coordinated ions and 3d1, 3d2, and 3d4 for the tetrahedrally coordinated ions. Section 3 deals with interconfigurational transitions of divalent and trivalent rare-earth
ions. Finally, in Sect. 4 the work is summarized.
Received: 22 December 2000 / Published online: 30 March 2001 相似文献
9.
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
10.
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
11.
De-Long Zhang Bei Chen Hong-Li Liu Yu-Ming Cui E.Y.B. Pun 《Applied Surface Science》2009,255(15):6930-6938
Polarized downconversion, 980-nm-upconversion and near-infrared emission characteristics of vapor-transport-equilibrated (VTEed) bulk Er (0.4 mol%)/MgO (6 mol%)-codoped LiNbO3 crystals were investigated. The downconversion and upconversion visible emissions display similar VTE effects including the drop of emission intensity and the weakening of polarization dependence. At 0.98 and 1.5 μm regions, the VTE has a weak effect on the emission intensity, but a strong effect on the spectral shape. The crystalline phases in these bulk Er/Mg-codoped VTE crystals are determined by comparing their infrared emission characteristics with those of pure ErNbO4 powder and locally Er-doped MgO (4.5 mol%):LiNbO3 crystal. The results show that the Er3+ ions present in these bulk Er/Mg-codoped VTE crystals as a mixture of Er:LiNbO3 and ErNbO4 phases. The percentages of the ErNbO4 phase contained in these VTE crystals were evaluated from the 1531 and 1536 nm characteristic absorption areas. The contents of constituent elements were determined by chemical analysis. 相似文献
12.
Alkali-earth-doped yttrium orthoaluminate crystals grown in a reducing atmosphere are found to show bright photoluminescence (PL) in visible wavelength regions under the excitation by UV light source. From the results of transmission, PL, PL excitation and time-resolved PL spectra for the samples with different types and concentrations of dopants and the comparison to the results for the samples grown under different conditions, the origin of principal emission is determined to be color centers stabilized by heterovalent ions. The observed fast lifetime and high quantum yield of the luminescence can be explained by dipole-allowed transition between the levels localized in a vacancy. Comparing the effects on the optical properties from several types of dopant ions and taking influence from the UV irradiation into account, a model for the structure of emission centers is proposed. 相似文献
13.
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
14.
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
15.
D.-L. Zhang C. Wu Q.-Z. Yang L. Sun Y.-H. Xu E. Y. B. Pun 《Applied physics. B, Lasers and optics》2009,95(2):335-340
Transient characteristics of upconverted emission (560 nm) of Er3+ in LiNbO3 crystals codoped with 0–7.4 mol% MgO were studied under pulse excitation at 800-nm wavelength. The results show that the
transients display considerable Mg-doping-level-dependent nonexponential behavior and a clear Mg optical-damage-resistance
threshold concentration effect. Below the Mg threshold concentration, the lifetime increases slightly with the increased Mg
concentration. Above the threshold, however, the lifetime drops abruptly by 4–7 times and the nonexponential feature becomes
more evident. It is found that each transient can be fitted by a double-exponential function contributed from isolated and
clustered Er3+ sites. The fit parameters show that doping of MgO above the threshold concentration increases the clustered Er site concentration
and the nonradiative cross relaxation probability. The Mg threshold concentration effect derived from the transients is in
qualitative agreement with that from the fluorescence spectrum measured as a function of the Mg concentration. The effect
of the Mg threshold concentration on the clustered Er site concentration is qualitatively explained on the basis of the microscopic
defect model of MgO:LiNbO3 and is conducted with the Mg site change around the threshold concentration. 相似文献
16.
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
17.
The luminescence properties of K3Tb(PO4)2 activated by Eu3+ were studied at excitation over the 120–300 nm wavelength range. It is demonstrated that Tb3+ ions, exhibiting a strong absorption band in the vacuum‐ultraviolet (VUV), can provide efficient sensitisation of Eu3+ emission in this wave length range, giving rise to intense red luminescence at 150 nm excitation. A proof is given for the concept of VUV sensitisation enabling the engineering of luminescence materials with enhanced conversion efficiency of VUV radiation into visible light. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
18.
C.P. Wyss W. Lüthy H.P. Weber V.I. Vlasov Y.D. Zavartsev P.A. Studenikin A.I. Zagumennyi I.A. Shcherbakov 《Applied physics. B, Lasers and optics》1998,67(5):545-548
4 as a host for thulium has several advantages for diode pumping in comparison with other crystals. The absorption cross section
of thulium in GdVO4 is considerably stronger and broader than in YAG and YLF and the spectrum is shifted closer to the emission wavelength of
commercially available AlGaAs laser diodes. In our paper, we report on the temporal and spectral emission properties of a monolithical
Tm30.01mm+([%at.]6.9):GdVO4 microchip laser at 1.9 μm. The laser can be adjusted to emit either cw or in an oscillating regime. Slope efficiencies up
to 47% are achieved. This value exceeds the Stokes limit of 42%.
Received: 31 March 1998/Revised version: 02 June 1998 相似文献
19.
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
20.
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