Direct measurement of the rate of nonradiative relaxation and luminescence spectra from the4G7/2,4G5/2+2G7/2, and4F9/2levels of Nd3+ions in LaF3, SrF2, and YAlO3laser crystals

AbstractFluoroindate glasses co-doped with Pr3+/Er3+ ions were synthesized and their near-infrared luminescence properties have been examined under selective excitation wavelengths. For the Pr3+/Er3+ co-doped glass samples several radiative and nonradiative relaxation channels and their mechanisms are proposed under direct excitation of Pr3+ and/or Er3+. The energy transfer processes between Pr3+ and Er3+ ions in fluoroindate glasses were identified. In particular, broadband near-infrared luminescence (FWHM = 278 nm) associated to the 1G4 → 3H5 (Pr3+), 1D2 → 1G4 (Pr3+) and 4I13/2 → 4I15/2 (Er3+) transitions of rare earth ions in fluoroindate glass is successfully observed under direct excitation at 483 nm. Near-infrared luminescence spectra and their decays for glass samples co-doped with Pr3+/Er3+ are compared to the experimental results obtained for fluoroindate glasses singly doped with rare earth ions.

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Near-infrared and visible luminescence and absorption spectroscopy of low-coordinate organometallic rhenium compounds

Canadian Journal of Chemistry ◽

10.1139/v96-003 ◽

1996 ◽

Vol 74 (1) ◽

pp. 28-31

Author(s):

Carole Savoie ◽

Christian Reber

Keyword(s):

Low Temperature ◽

Near Infrared ◽

Organic Ligands ◽

Luminescence Spectra ◽

Relaxation Processes ◽

Nonradiative Relaxation ◽

Visible Luminescence ◽

Infrared Spectral ◽

Absorption And Luminescence Spectra ◽

Stokes Shifts

Low-temperature absorption and luminescence spectra of four organorhenium compounds were measured in the visible and near-infrared spectral regions. Effects of the temperature, formal oxidation state, and the oxo-, bromo-, and organic ligands on the metal center are reported. The emission maxima of the four compounds show a large variation between 9000 and 14 200 cm−1. Stokes shifts show a smaller variation from 3700 to 4200 cm−1. Luminescence intensities are used to qualitatively characterize nonradiative relaxation processes. Key words: luminescence spectra, absorption spectra, organorhenium compounds.

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Direct Measurement of the Listening of Hearing-Impaired Children

Journal of Speech and Hearing Research ◽

10.1044/jshr.1301.65 ◽

1970 ◽

Vol 13 (1) ◽

pp. 65-73 ◽

Cited By ~ 5

Author(s):

Mary Mira

Keyword(s):

Direct Measurement ◽

Continuous Measurement ◽

Hearing Impaired ◽

Reinforcement System ◽

School Aged Children ◽

Conjugate Reinforcement ◽

Impaired Children ◽

Hearing Impaired Children

Listening, a significant dimension of the behavior of hearing-impaired children, may be measured directly by recording childrens' responses to obtain audio narrations programmed via a conjugate reinforcement system. Twelve hearing-impaired, school-aged children responded in varying ways to the opportunity to listen. Direct and continuous measurement of listening has relevance for evaluation of remediation methods and for discovery of variables potentially related to listening.

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