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

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