Gupta, Gaurav and Balaji, Sathravada and Biswas, Kaushik and Annapurna, K (2019) Frequency upconversion mechanism in Ho3+/Yb3+-codoped TeO2-TiO2-La2O3 glasses. Applied Physics B-Lasers and Optics, 125 (2). Art No-28. ISSN 0946-2171

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Abstract

Frequency upconversion from Ho3+/Yb3+-codoped glass or crystal under Yb3+ sensitization is a known phenomenon. However, inconsistencies are prevalent in the understanding of double energy transfer mechanisms for Ho3+/Yb3+-codoped systems. In this context, rate equations are proposed for Ho3+/Yb3+-codoped low-phonon TeO2-TiO2-La2O3 glass under Yb3+ sensitization with continuous and pulsed excitations. The proposed rate equations are validated with experimental results to elucidate the mechanisms responsible for populating (5)(S-2, F-4) and F-5(5) energy levels of Ho3+ ion. The solutions of rate equations with experimental results are substantiating the occurrence of both excited state absorption (ESA) and energy transfer upconversion (ETU) mechanisms in populating Ho3+:5(S-2, F-4) level, though higher concentration of Ho3+ ion would decrease the probability of ETU and increase of ESA. In contrast, Ho3+:5F5 level has been populated via ETU only. Numerical solutions to the rate equations are also proposed to elucidate the mechanics for populating (5)(S-2, F-4) and F-5(5) levels of Ho3+ ion. The proposed rate equation for pulsed excitation explains the characteristics of respective decay curves, which are further used to quantify energy transfer coefficient (W-02) as (1.77 +/- 0.12)x10(-17)cm(3)s(-1) for Ho3+/Yb3+-codoped TTL glass host.

Item Type:	Article
Subjects:	Glass
Divisions:	Glass
Depositing User:	Bidhan Chaudhuri
Date Deposited:	14 Nov 2019 09:36
Last Modified:	14 Nov 2019 09:36
URI:	http://cgcri.csircentral.net/id/eprint/4600

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