Browsing by Author "Rambabu, U"

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Emission spectra of LnPO(4): RE3+ (Ln = La, Gd; RE = Eu, Tb and Ce) powder phosphors
(2003-02-03)
Rambabu, U
;
Munirathnam, NR
;
Prakash, TL
;
Buddhudu, S
;
光電工程學系
This paper reports the emission spectra at room temperature and presents an optimum concentration for each of the dopants in GdPO4:Eu3+, LaPO4:Tb3+ and LaPO4:Ce3+ powder phosphors for the observation of bright reddish-orange, green and UV emission, respectively. FT-IR and a thermal analysis of these phosphor materials have been carried out. Scanning electron microscopic investigations were also conducted to understand surface morphological features (shape) and the grain size in the powder phosphor systems. (C) 2002 Elsevier Science B.V. All rights reserved.
Fabrication and nonlinear optical properties of nanoparticle silver oxide films
(2003-08-01)
Chiu, Y
;
Rambabu, U
;
Hsu, MH
;
Shieh, HPD
;
Chen, CY
We report the fabrication of nanoparticle silver oxide thin films by rf magnetron sputtering and characterization of their nonlinear optical properties. The chemical decomposition and reversibility of AgOx compounds were studied by thermogravimetric analysis, differential scanning calorimetry, and x-ray diffraction. Electron spectroscopy for chemical analysis measurements revealed a 0.5 eV negative binding energy shift from AgO to Ag2O phase. The effect of particle plasmon resonance was confirmed by the absorption band shift with increased Ag2O Particle size. The measured third-order nonlinear susceptibility (chi(3) = 3.4 x 10(-7) esu) and response time (27 ps) of the Ag2O nanoparticles makes it promising for applications in all-optical switching devices and optical data storage systems. (C) 2003 American Institute of Physics.