Enhancement of upconversion intensity in Er3+ doped tellurite glass in presence of Yb3+

Applied Physics B (Impact Factor: 1.63). 07/2011; 104(1):233-236. DOI: 10.1007/s00340-011-4422-6

ABSTRACT TeO2–PbO glasses doped/codoped with Er3+/Er3+-Yb3+ ions have been fabricated by melting and quenching method. Efficient frequency upconversion emissions spanning from blue
to red regions corresponding to the 2H11/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions, respectively, upon excitation with 976 nm diode laser radiation have been observed. The variations observed
in the intensity of whole upconversion emission spectra due to the presence of the Yb3+ ions are reported and discussed in detail.

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    ABSTRACT: This article reports on the visible upconversion and temperature sensing behaviour of Er3+-Yb3+ doped/codoped TeO2-WO3 glasses prepared by a melting and quenching method. The upconversion emissions have been observed throughout the visible and infrared region upon 980 nm and 808 nm excitations and assigned suitably from different transitions of the Er3+ ion. The emission intensities have been enhanced about 5.92 and 3.99 times for most intense green band upon 980 and 808 nm excitations, respectively on codoping with Yb3+ ions. The reason behind this improvement is explained on the basis of a power dependence study and an energy level structure. The colour tunability behaviour of the codoped glass has also been investigated upon both excitations. The temperature sensing performance of the prepared glass has been studied by using the fluorescence intensity ratio technique upto 745 K. The results suggested that the present glass is a suitable candidate for making a high temperature sensor up to 690 K with a sensitivity of about 28.72×10-4 K-1.
    Sensors and Actuators B Chemical 06/2014; 202. DOI:10.1016/j.snb.2014.06.074 · 3.84 Impact Factor
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    ABSTRACT: The multicolor intense visible emission from Er3+ and Tm3+ ions codoped in TeO2–PbO glass upon excitation at ∼1064 nm radiation from a nanosecond pulsed Nd:YAG laser has been investigated. The optical parameters of erbium ions codoped in Tm3+–TeO2–PbO glass by using the Judd–Ofelt theory have been determined from the optical absorption spectra. No upconversion (UC) emission was seen in the singly doped Er3+-doped glass upon excitation at 1064 nm. Through the experiments, it has been found that, in the codoped glass, the UC luminescence from Er3+ (2.0 mol. %) in green and red regions corresponding to the H211/2→I415/2, S43/2→I415/2, and F49/2→I415/2 transitions is strengthened about ∼40, ∼60, and ∼130 fold, respectively, at 2.0 mol. % Tm3+ ion concentration in codoped glass. The observed UC emissions and the enhancement observed in their intensity have been explained on the basis of efficient energy transfer and cross-relaxation energy transfer processes.
    Journal of the Optical Society of America B 04/2014; 31(5). DOI:10.1364/JOSAB.31.001041 · 1.81 Impact Factor
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    ABSTRACT: The present paper covers a detail explanation about the laser induced optical heating and temperature sensing ability of intense green upconversion emitting Er3+–Yb3+ codoped SrWO4 phosphor. The structural studies based on X-ray diffraction and Fourier transform infrared analysis confirmed the phase formation, crystallinity and the presence of vibrational bands of the corresponding host lattice. The optical investigation was performed by recording the diffuse reflectance and upconversion emission spectra upon a 980 nm excitation. Multiphoton upconversion processes were confirmed by pump power dependence study for the various emission bands throughout the visible region. Optical thermometry has been performed using the fluorescence intensity ratio technique in which two thermally coupled levels of the green emission bands were used. A relatively low temperature (518 K) sensor with very high sensor sensitivity (14.98 × 10−3 K−1) is determined from the observed results. The optical heating ability of the synthesized phosphor is also determined by using the results of the optical thermometry and found the heat generation up to ∼417 K. The results obtained may possibly be used in cancer therapy.
    Sensors and Actuators B Chemical 01/2015; 209:352. DOI:10.1016/j.snb.2014.11.126 · 3.84 Impact Factor