Agata Baranowska

Structural and optical properties of antimony-germanate-borate glass and glass fiber co-doped Eu3+ and Ag nanoparticles

In the paper analysis of structural and luminescent properties of antimony-germanate-borate glasses and glass fiber co-doped with 0.6AgNO3/0.2Eu2O3are presented. Heat treatment of the fabricated glass and optical fiber (400 °C, 12 h) enabled to obtain Ag nanoparticles (NPs) with average size 30-50 nm on their surface. It has been proofed that silver ions migrate to the glass surface, where they are reduced to Ag0 nanoparticles. Simultaneously, FTIR analysis showed that heat treatment of the glass and optical fiber increases the local symmetry of the Eu3+ site.

Optical Characterization of Nano- and Microcrystals of EuPO4 Created by One-Step Synthesis of Antimony-Germanate-Silicate Glass Modified by P2O5

Technology of active glass-ceramics (GC) is an important part of luminescent materials engineering. The classic method to obtain GC is based on annealing of parent glass in proper temperature and different time periods. Generally, only the bulk materials are investigated as a starting host for further applications. However, the effect of an additional heat-treatment process on emission and structural properties during GC processing is omitted. Here, we focus on the possibility of obtaining transparent glass-ceramic doped with europium ions directly with a melt-quenching method. The influence of phosphate concentration (up to 10 mol %) on the inversion symmetry of local environment of Eu3+ ions in antimony-germanate-silicate (SGS) glass has been investigated. The Stark splitting of luminescence spectra and the local asymmetry ratio estimated by relation of (5D0→7F2)/(5D0→7F1) transitions in fabricated glass confirms higher local symmetry around Eu3+ ions. Based on XRD and SEM/EDX measurements, the EuPO4 nano- and microcrystals with monoclinic geometry were determined. Therefore, in our experiment, we confirmed possibility of one-step approach to fabricate crystalline structures (glass-ceramic) in Eu–doped SGS glass without additional annealing process.

Capillary optical fibre with Sm3+ doped ribbon core

The paper presents new construction of luminescent photonic sensor based on an optical fiber capillary with a side ribbon doped with Sm3+ ions. Samarium ions ensure efficient excitation at the wavelength of 405 nm and multi colour luminescence in visible spectrum (550-720 nm). This phenomenon was proposed to increase sensor accuracy by using measurements of certain wavelength. The luminescence and angular characteristics of developed optrode were characterized at the lateral and face excitation of special capillary fibre construction. Rhodamine B (RhB) was used as a test solution in designed optrode. The nearly linear characteristic of RhB concentration was obtained for up to 0.15 % (w/w). The results indicate that the designed optrode can be used for construction of compact luminescent sensor for measuring selected properties of the solutions.

Effect of alkali content on spectroscopic properties of Er/Ag co-doped antimony-germanate glasses

In this work, thermal and spectroscopic properties of antimony-germanate glasses have been presented. Investigated glasses with the different molar content of alkalis (Na2O and K2O) have been co-doped with erbium and silver ions in order to obtain luminescence in the near-infrared region. Along with the increment of alkalis content, an increase of thermal stability parameter ΔT has been observed. High concentration of Na2O and K2O in the glassy matrix results in the presence of a plasmonic peak at the wavelength of 454 nm originating from large volume fraction of silver nanoparticles. Change of the luminescence parameters in the near-infrared region (Er3+: 4 I13/2→4I15/2) has been observed in the function of alkalis content in the glass matrix, which high concentration increases the volume fraction and size of silver nanoparticles promoting the energy transfer channel Er3+→Ag.

Effect of biodegradation on spectroscopic properties of Sm3+ doped 45S5 bioglass

In the article, we showed the unconventional method to determine the degradation of Bioglass 45S5 doped with samarium ions used as an optical probe. The strongest emission at the wavelength of 601 nm has been observed under 405 nm laser excitation. We used the alternative method of fiber drawing from the 45S5 glass. Bioactive glass fiber was immersed in Sorensen buffer at temperature 37°C. In situ analysis of luminescence signal of glass fiber shown a decrease in intensity within 24 hours. This effect was connected with partial surface degradation of bioglass fiber.

Optical fiber head for monitoring of heart rate and blood oxygenation

In this article we presented possibility of heart rate and blood oxygenation measurements by classic displacement optical fiber sensor in reflection mode. Based on numerical analysis of sensor head characteristics the optimal construction was developed. Three LED diodes at the wavelengths of 530nm (green), 650nm (red) and 850nm (infrared) were used for determine heart rate and saturation of blood during “in vivo” measurements. Developed sensor head allows noninvasive and continuously monitoring of blood parameters.