Analysis of upconversion processes in germanate and tellurite glasses codoped with Yb³⁺/Ho³⁺

Abstract

In this paper the analysis of upconversion luminescence dynamics in tellurite and germanate glasses doped with Ho 3+ and sensitized by Yb 3+ in 8:1 molar ratio was presented. Population of energy levels was calculated using Runge-Kutta method. The influence of pump power (976 nm) radiation on population of excited levels and the possible upconversion mechanisms were analyzed. The energy transfer coefficient in tellurite glass C D2 = 5,0 x 10 -18 cm 3 /s, C D3 = 1,5 x 10 -17 cm 3 /s and C D4 = 9,0 x 10 -17 cm 3 /s and in germanate glass C D2 = 2,80 x 10 -18 cm 3 /s, C D3 = 6,35 x 10 -18 cm 3 /s and C D4 = 3,56 x 10 -17 cm 3 /s were used to analyze dynamics of upconversion processes.

Active structural waveguide for sensing application

“…A new solution proposed by authors is to develop the construction of the active microstructural fiber, where the evanescent wave field of the luminescence signal interacts with tested liquid that is in holes of the fiber. The near infrared radiation (NIR) to visible upconversion in elaborated microstructural fiber co-doped with Yb 3+ /Tm 3+ allowed to utilize emission in the range of 480 nm and 650 nm as operating signal of sensor [12][13][14][15][16][17]. An analysis of possibilities of using the fabricated optical fiber to measure the concentration of fluorescein aqueous solutions showed that developed optical fiber construction enables to measurement of the concentration in the range of (0.25 -5.42) [10 -4 mol%] and sensitivity of optrode is 1.51 10 4 [1/mol%].…”