Active structural waveguide for sensing application

Abstract

In the article a microstructural active optical fiber for sensing application was presented. Construction consists of three hexagonal rings and a core made of SiO 2 -Al 2 O 3 -Sb 2 O 3 glass co-doped with 1Yb 2 O 3 /0.1Tm 2 O 3 [mol%]. Developed optical fiber is characterized by upconversion luminescence (λ p =980nm) at 480nm (Tm 3+ : 1 G 4 → 3 H 6 ) and 650 nm (Tm 3+ : 1 G 4 → 3 F 4 ). Population of thulium levels was attained in result of the Yb 3+ →Tm 3+ upconversion energy transfer. Sensing application of elaborated active photonic structure was presented on the example of aqueous fluorescein solution. Fabricated microstructural optical fiber enables to measure of the fluorescein solutions with the concentration of (0.25 -5.42)·10 -4 [mol%]. Sensitivity of the elaborated measurement setup is 1.51·10 4 [1/mol%].