Tellurite-zinc glasses doped with Er3+, Yb3+ and Tm3+ were fabricated by conventional melt-quenching technique and characterised by absorption spectroscopy, refractive index, lifetime measurements, excitation, luminescence and up-conversion spectroscopy. Tunable blue to cold white light emission based on the colour mixing of red, green and blue light was obtained via up-conversion under 980 nm and by adjusting the laser excitation intensity. The balancing of the relative intensity of each colour is provided by the energy transfer process between the rare-earth ions. Moreover, luminescence spectroscopy was performed with a 405 nm laser to further understand the energy transfer mechanism that produce the white light. The Judd-Ofelt intensity parameters (Ω2, Ω4 and Ω6) were calculated for all samples and present the trend Ω2>Ω4>Ω6. The spectroscopic parameters were computed with the Judd-Ofelt theory as well as the energy transfer micro-parameters (critical radius of interaction and energy transfer coefficient). Such results shall be used to give a comprehensive explanation for the energy transfer process between these rare earth ions.
Bibliographical noteFunding Information:
This research was supported by the S?o Paulo Research Foundation (FAPESP) under the grant 2013/07276-1 and ConselhoNacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) through the Centro de Pesquisa em ?ptica e Fot?nica (CePOF) - S?o Paulo - Brazil (processes 310925/2017-7 and 133451/2018-6).
This research was supported by the São Paulo Research Foundation (FAPESP) under the grant 2013/07276-1 and ConselhoNacional de Desenvolvimento Científico e Tecnológico ( CNPq ) through the Centro de Pesquisa em Óptica e Fotônica ( CePOF ) - São Paulo - Brazil (processes 310925/2017-7 and 133451/2018-6 ).
- Energy transfer
- White light