Marcin Kochanowicz

Coherent beam combining of active multicore optical fiber

In the paper the phase - locked emitters in multicore optical fibers for high power fiber lasers are presented. The simulation of coupling coefficient between cores influences on phase - locking and in the consequence on the far field pattern of the fiber laser based on the analyzed mutlicore optical fiber were performed. In the analyzed fiber laser, while exchanging power of the generated radiation between two adjacent cores on the fiber length (L=5m) within the range of 4% - 10%, the radiation becomes phased. Having satisfied this condition, in the far -field low-divergence, high-power laser beam (supermode) is attained.

Upconversion luminescence in tellurite optical fiber codoped with Yb3+/Ho3+ ions

In the article the spectroscopic properties of Yb3+/Ho3+ codoped tellurite glass has been investigated. Upconversion luminescence at the wavelengths of 545 nm (5S2 (5F4) → 5I8) and 654 nm (5F5 → 5I8) in holmium ion was obtained as a result of energy transfer between Yb3+ and Ho3+ ions. Elaborated tellurite glass characterized by highest intensity of upconversion luminescence (0.5mol% Yb2O3/0.1mol% Ho2O3) was used as core of double-clad optical fiber. The amplified spontaneous emission in the fabricated optical fiber resulting from the optical transition in the structure of holmium was observed. The intensity of the emission band at the wavelength of 545 nm (5S2 (5F4)→ 5I8) of the fabricated optical fiber was several times smaller than the intensity of the emission band at 657 nm (5F5→ 5I8).

The Luminescent Properties of Photonic Glasses and Optical Fibers

In this chapter, the visible luminescent properties of antimony-germanate and gallo-germanate glasses, glass-ceramics and optical fibers co-doped with different rare-earth (RE) systems (e.g., Sm3+, Eu3+, Yb3+/Tm3+, Yb3+/Ho3+, Yb3+/Tm3+/Ho3+, Yb3+/Tb3+, Yb3+/Eu3+) have been analyzed. Emission was obtained by direct excitation of RE ions or in case of co-doped systems by donor-acceptor energy transfer and upconversion processes. Novel constructions of double-clad, offset core, double-core, and RE triply doped optical fibers have been presented. Moreover, the effect of the structure modification of antimony-germanate glasses on the luminescence shaping has been also presented. Another, presented scientific area is investigation of plasmon effect in Ag0/Eu3+ co-doped glasses and optical fibers. The optimization of Ag0/Eu3+ content and formation of silver nanoparticles process (thermal annealing) in order to enhance luminescence has been presented.

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.

Spectroscopic properties of rare earth doped germanate glasses

Structural and optical properties of Eu3+ doped barium-gallo-germanate glasses modified with antimony and tellurium oxides were investigated. Barium ions are gradually replaced by antimony and tellurium ions to create two glass series. Structural properties of prepared series were established with help of FT-IR spectroscopy, X-ray diffraction method and observation under Scanning Electron Microscope (SEM). MIR spectra of studied glasses indicate a tendency to glass structure polymerization through the observed shift of main band assigned to Ge-O-Ge and Ge-O bonds vibrations. Simultaneously luminescence spectrum of Eu3+ ion (Electric/Magnetic – ED/EM dipole transition intensity ratio) for both glass series presented the increasing tendency to ordering of Eu3+ local environment. It was also proved that tetrahedral [TeO4] units were created in glass structure which were modified with TeO2 when addition exceed 10 mol%. The result indicates decrease of ED/MD ratio as a function of TeO2 content above its 10 mol%.