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Title: Random lasing in Nd{sup 3+} doped potassium gadolinium tungstate crystal powder

Abstract

Random laser (RL) emission in Nd{sup 3+} doped potassium gadolinium tungstate—KGd(WO{sub 4}){sub 2}:Nd{sup 3+}—crystal powder is demonstrated. The powder was excited at 813 nm in resonance with the Nd{sup 3+} transition {sup 4}I{sub 9/2}→{sup 4}F{sub 5/2}. RL emission at 1067 nm due to the {sup 4}F{sub 3/2}→{sup 4}I{sub 11/2} transition was observed and characterized. An intensity threshold dependent on the laser spot area and bandwidth narrowing from ≈2.20 nm to ≈0.40 nm were observed and measured. For a beam spot area of 0.4 mm{sup 2}, a RL threshold of 6.5 mJ/mm{sup 2} (90 MW/cm{sup 2}) was determined. For excitation intensity smaller than the RL threshold, only spontaneous emission from level {sup 4}F{sub 3/2} with decay time in the tens microsecond range was observed, but for excitation above the RL threshold, significant shortening of excited level lifetime, characteristic of a stimulated process was found. The overall characteristics measured show that KGd(WO{sub 4}){sub 2}:Nd{sup 3+} is an efficient material for operation of solid state RLs in the near-infrared.

Authors:
 [1];  [2];  [3];  [4]; ; ;  [3]; ;  [5]
  1. Grupo de Física da Matéria Condensada, Núcleo de Ciências Exatas – NCEx, Campus Arapiraca, Universidade Federal de Alagoas, 57309-005, Arapiraca, AL (Brazil)
  2. (Brazil)
  3. Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil)
  4. (Cameroon)
  5. Institute for Lasers, Photonics and Biophotonics, The State University of New York, Buffalo, New York 14260-3000 (United States)
Publication Date:
OSTI Identifier:
22413148
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTALS; DOPED MATERIALS; EXCITATION; EXCITED STATES; GADOLINIUM TUNGSTATES; LASER RADIATION; LIFETIME; NEODYMIUM IONS; NEODYMIUM TUNGSTATES; POTASSIUM TUNGSTATES; POWDERS; SOLIDS

Citation Formats

Moura, André L., E-mail: andre.moura@fis.ufal.br, Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Fewo, Serge I., Laboratory of Mechanics, Department of Physics, University of Yaoundé I, Yaoundé, Carvalho, Mariana T., Gomes, Anderson S. L., Araújo, Cid B. de, Kuzmin, Andrey N., and Prasad, Paras N. Random lasing in Nd{sup 3+} doped potassium gadolinium tungstate crystal powder. United States: N. p., 2015. Web. doi:10.1063/1.4913390.
Moura, André L., E-mail: andre.moura@fis.ufal.br, Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Fewo, Serge I., Laboratory of Mechanics, Department of Physics, University of Yaoundé I, Yaoundé, Carvalho, Mariana T., Gomes, Anderson S. L., Araújo, Cid B. de, Kuzmin, Andrey N., & Prasad, Paras N. Random lasing in Nd{sup 3+} doped potassium gadolinium tungstate crystal powder. United States. doi:10.1063/1.4913390.
Moura, André L., E-mail: andre.moura@fis.ufal.br, Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Fewo, Serge I., Laboratory of Mechanics, Department of Physics, University of Yaoundé I, Yaoundé, Carvalho, Mariana T., Gomes, Anderson S. L., Araújo, Cid B. de, Kuzmin, Andrey N., and Prasad, Paras N. Sat . "Random lasing in Nd{sup 3+} doped potassium gadolinium tungstate crystal powder". United States. doi:10.1063/1.4913390.
@article{osti_22413148,
title = {Random lasing in Nd{sup 3+} doped potassium gadolinium tungstate crystal powder},
author = {Moura, André L., E-mail: andre.moura@fis.ufal.br and Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE and Fewo, Serge I. and Laboratory of Mechanics, Department of Physics, University of Yaoundé I, Yaoundé and Carvalho, Mariana T. and Gomes, Anderson S. L. and Araújo, Cid B. de and Kuzmin, Andrey N. and Prasad, Paras N.},
abstractNote = {Random laser (RL) emission in Nd{sup 3+} doped potassium gadolinium tungstate—KGd(WO{sub 4}){sub 2}:Nd{sup 3+}—crystal powder is demonstrated. The powder was excited at 813 nm in resonance with the Nd{sup 3+} transition {sup 4}I{sub 9/2}→{sup 4}F{sub 5/2}. RL emission at 1067 nm due to the {sup 4}F{sub 3/2}→{sup 4}I{sub 11/2} transition was observed and characterized. An intensity threshold dependent on the laser spot area and bandwidth narrowing from ≈2.20 nm to ≈0.40 nm were observed and measured. For a beam spot area of 0.4 mm{sup 2}, a RL threshold of 6.5 mJ/mm{sup 2} (90 MW/cm{sup 2}) was determined. For excitation intensity smaller than the RL threshold, only spontaneous emission from level {sup 4}F{sub 3/2} with decay time in the tens microsecond range was observed, but for excitation above the RL threshold, significant shortening of excited level lifetime, characteristic of a stimulated process was found. The overall characteristics measured show that KGd(WO{sub 4}){sub 2}:Nd{sup 3+} is an efficient material for operation of solid state RLs in the near-infrared.},
doi = {10.1063/1.4913390},
journal = {Journal of Applied Physics},
number = 8,
volume = 117,
place = {United States},
year = {Sat Feb 28 00:00:00 EST 2015},
month = {Sat Feb 28 00:00:00 EST 2015}
}
  • The 5 at.% Nd{sup 3+}-doped potassium ytterbium tungstate (Nd{sup 3+}:KYb(WO{sub 4}){sub 2}, hereafter Nd:KYbW) laser crystal with the dimension up to 28 mm x 15 mm x 12 mm was grown by the top seeded solution growth (TSSG) method. The infrared spectrum of crystal sample was measured, and the vibrational peaks were assigned. According to the absorption and emission spectra of crystal sample, the absorption and emission cross-sections are 16.03 x 10{sup -20} cm{sup 2} at 808 nm and 10.72 x 10{sup -20} cm{sup 2} at 1067 nm, respectively. The fluorescence life of {sup 4}F{sub 3/2} energy level is 196.33more » {mu}s, and the fluorescence branching ratio for the {sup 4}F{sub 3/2}-{sup 4}I{sub 11/2} transition at 1067 nm is 55.74%. The energy transfer between Nd{sup 3+} and Yb{sup 3+} ions was observed from the fluorescence spectra pumped by 808 and 980 nm LD sources and the Stark levels of Yb{sup 3+} in Nd:KYbW crystal were determined. Highly efficient laser output up to 305 mW of Nd:KYbW crystal at 1067 nm has been achieved under pumping by a CW 808 nm laser diode at room temperature. The optical-optical conversion efficiency is 33.9% and the slope efficiency is 46.8%.« less
  • Lasing is obtained in Tm{sup 3+}-doped sodium-gadolinium tungstate NaGd(WO{sub 4}){sub 2} crystals longitudinally pumped by pulses from a laser diode bar. The slope lasing efficiency is 16%. Lasing was observed at wavelengths of 1957, 1944, 1936, and 1901 nm for the transmission coefficients of the output mirror T{sub out} = 0.3%, 1.4%, 3.3%, and 8.5%, respectively. (lasers)
  • The lasing efficiency of Nd{sup 3+} ions is studied in laser materials capable of self-Raman frequency conversion. The lasing properties of tungstate and molybdate crystals with the scheelite structure (SrWO{sub 4}, BaWO{sub 4}, PbWO{sub 4}, SrMoO{sub 4}, PbMoO{sub 4}) activated with neodymium ions are investigated upon longitudinal pumping by a 750-nm alexandrite laser or a 800-nm diode laser. The slope lasing efficiency obtained for a Nd{sup 3+}:PbMoO{sub 4} laser emitting at 1054 nm is 54.3% for the total lasing efficiency of 46%, which is the best result for all the crystals with the scheelite structure studied so far. The simultaneousmore » Q-switched lasing and self-Raman frequency conversion were demonstrated in neodymium-doped SrWO{sub 4}, PbWO{sub 4}, and BaWO{sub 4} crystals. (papers devoted to the 90th anniversary of a.m.prokhorov)« less
  • Multi-mode random lasing action and weak localization of light were evidenced and studied in normally transparent but disordered Nd{sup 3+} doped (Pb,La)(Zr,Ti)O{sub 3} ceramics. Noticeable localized zone and multi-photon process were observed under strong pumping power. A tentative phenomenological physical picture was proposed by taking account of diffusive process, photo-induced scattering, and optical energy storage process as dominant factors in elucidating the weak localization of light observed. Both the decreased transmittance (increased reflectivity) of light and the observed long lasting fading-off phenomenon supported the physical picture proposed by us.
  • The generation in a laser with an active element made of a neodymium-doped potassium - gadolinium tungstate crystal Nd{sup 3+}:KGW in the form of a parallelepiped with a coaxial hole for a pump flashlamp is studied. The effect of anisotropy of spectral and laser properties of a Nd{sup 3+}:KGW laser and of the thermal inhomogeneity of the distribution of laser emission on the output mirror is experimentally demonstrated under conditions when the pump radiation virtually does not return to the medium (the unlimited aperture model). (lasers and amplifiers)