Spectroscopy and gain measurements of Nd sup 3+ in SrF sub 2 and other fluorite-structure hosts

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Journal of the Optical Society of America, Part B: Optical Physics; (USA)

DOI:https://doi.org/10.1364/JOSAB.8.000726· OSTI ID:5590096

Payne, S A; Caird, J A; Chase, L L; Smith, L K; Nielsen, N D; Krupke, W F ^[1]

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1. Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (US)

We investigate the optical properties of Nd{sup 3+} in CaF{sub 2}, SrF{sub 2}, and BaF{sub 2} with the intent of determining if any of these materials might usefully serve as a laser-pumped-amplifier medium. The Nd{sup 3+} impurities tend to cluster at extremely low levels of doping in CaF{sub 2}, leading to the formation of nonluminescent centers. The addition of La or Y buffer ions to CaF{sub 2}:Nd serves to increase the luminescent yield, but it also renders the system spectrally inhomogeneous. Although single-ion centers predominate in BaF{sub 2}, the interstitial fluoride compensator occurs at the next-nearest-neighbor position relative to Nd{sup 3+}, leading to unsuitably low transition strengths. The interstitial fluoride occurs at the nearest-neighbor site of Nd{sup 3+} in SrF{sub 2} and thereby induces significant oscillator strength into the 4f--4f transitions by breaking the inversion symmetry. The radiative lifetime of SrF{sub 2}:Nd is found to be 1470 {mu}sec by measuring the emission lifetime and quantum efficiency; this value was confirmed by Judd--Ofelt analysis of the absorption features. The peak-emission cross section at room temperature was determined to be 1.7{times}10{sup {minus}20} cm{sup 2} at 1036.5 nm. A maximum of 0.20 at. % Nd{sup 3+} may be doped into SrF{sub 2} without the occurrence of significant Nd clustering. Direct measurements of the gain spectrum in SrF{sub 2}:Nd reveal the presence of the {sup 4}F{sub 3/2} {r arrow} {sup 2}G{sub 9/2} excited-state absorption, although its impact on the emission cross section is only minor.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5590096
• Journal Information: Journal of the Optical Society of America, Part B: Optical Physics; (USA), Journal Name: Journal of the Optical Society of America, Part B: Optical Physics; (USA) Vol. 8:4; ISSN JOBPD; ISSN 0740-3224
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
42 ENGINEERING
426002 -- Engineering-- Lasers & Masers-- (1990-)
440600 -- Optical Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
ABSORPTION SPECTRA
ALKALINE EARTH METAL COMPOUNDS
AMPLIFICATION
BARIUM COMPOUNDS
BARIUM FLUORIDES
CALCIUM COMPOUNDS
CALCIUM FLUORIDES
CALCIUM HALIDES
CHARGED PARTICLES
EMISSION SPECTRA
FLUORIDES
FLUORINE COMPOUNDS
GAIN
HALIDES
HALOGEN COMPOUNDS
IONS
LUMINESCENCE
NEODYMIUM IONS
OPTICAL PUMPING
PUMPING
SPECTRA
SPECTROSCOPY
STRONTIUM COMPOUNDS
STRONTIUM FLUORIDES