Jan Kucharski

PbO-Bi2O3-Ga2O3-BaO-Dy3+ glasses for IR luminescence

Infrared luminescence from Dy3+ ions embedded in PbO–Bi2O3–Ga2O3–BaO glass hosts is reported for room and helium liquid temperatures. The substantial influence of energy transfer processes between the glass host and Dy3+ ions is shown experimentally through the dependences of photoluminescence on light polarization and excitation wavelength. Only polarized excited pulsed YAG-Nd laser light (λ=714nm) gives substantial IR luminescence with efficiency up to 41%. The role of the phonon-relaxation subsystem in the observed luminescence is discussed.

Eu3+-doped glass materials for red luminescence

Abstract Red luminescence (at wavelength about 622 nm ) from Eu3+ ions embedded in PbO–Bi2O3–Ga2O3–BaO glass hosts is reported for room and liquid helium temperatures. The substantial influence of energy transfer processes between the host and Eu3+ ions is shown experimentally through the dependences of photoluminescence on light polarization and excitation wavelength. Only polarized, excited pulsed XeII laser light (λ=714 nm ) gives substantial luminescence with efficiency up to 14.3%. The role of phonon-relaxation subsystem in the observed luminescence is discussed.

PbO–Bi2O3–Ga2O3–BaO glasses doped by Er3+ as novel materials for IR emission

Abstract Infra-red luminescence (at wavelengths about 1600 and 2500 nm ) from Er3+ ions embedded in PbO–Bi2O3–Ga2O3–BaO glass hosts is reported for room and helium liquid temperatures. The substantial influence of energy transfer processes between the host and Er3+ ions is shown experimentally through the dependences of photoluminescence on light polarization and excitation wavelength. Only the application of the polarized pumping YAG–Nd laser beam (λ=1060 nm ) stimulates substantial luminescence with quantum efficiency up to 24%. The role of phonon-relaxation subsystem in the observed luminescence is discussed.

Glass of high refractive index for optics and optical fiber

Halide-chalcogenide glasses whose properties make them suitable for applications in modern optics and optical fiber technique are investigated. The object of examination were oxygen-free glasses in the Sb2Se3-BaCl2-PbCl2 system. Because of the unconventional method of obtaining these glasses (great difficulties connected with passing into the glassy state) a special method of synthesizing these glasses is developed. Their characteristic temperatures and thermal stabilities are determined. Structural investigations using IR spectroscopy are carried out and the phase composition following the crystallization of the glasses is established by x-ray examination. Certain properties of the glasses are investigated, giving special consideration to the optical properties (refractive index and transmission in the far-IR range). The investigation results reveal the possibility of producing stable glasses, a few millimeters thick, using a special method of synthesis. The absorption bands in the IR spectra of the examined glasses are attributed to the symmetric and asymmetric vibrations of the Sb-Se-Sb bridge. The transmission range of the obtained glasses falls within the limit 0.65 to 50 ?m, at the level of 38 to 60%, and the refractive index is n > 2.5. Material of such properties offers the possibility to obtain optical fibers of very high numerical aperture and special applications are possible because of a wide transmission range.

Photoinduced phenomena in Sb2Se3-BaCl2-PbCl2 glasses

Photoinduced optical phenomena in amorphous Sb2Se3- BaCl2-PbCl2 glasses have been studied using experimental spectroscopic and theoretical quantum chemical methods. Photo-induced two-photon absorption (TPA) and second harmonic generation (SHG) were measured for the probing CO2-laser wavelength 10.6 micrometers . CO-laser ((lambda) equals 5.5 micrometers ) was used as a source of photoinducing light. We have found that with an increasing CO-laser exposure the SHG maximum output signal increases and achieves its maximum values at CO photon fluence 18 * 1013 phot./cm2 after the two hours of illumination. The absolute SHG values were not more than one order less comparing with ZnS crystals in case of its third rank nonlinear optical susceptibility tensor components (chi) 222 ((lambda) equals 10.6 micrometers ). With decreasing temperature the SHG signal strongly increases within the 32...26 K temperature range. Time-dependent probe-pump measurements indicate on existence of SHG maximum at time delay about 45 ps. Good correlation between SHG and TPA was observed. Simultaneously spectra positions of TPA maxima are strongly depended on the photoinduced fluence. Contrary to the SHG behavior for the TPA we observe at least two maxima at 26 ps and 70 p.s We explain this dependence within a framework of the quantum chemical approach with taken into account of anharmonic electron-vibrational interaction. Coming out from the performed calculations and IR-spectroscopy Fourier technique measurements in the spectral region between 100 cm-1 and 300 cm-1 we have ascertained a key role of Sb-Se fragments in the observed photoinduced effects. A stage of the reversible photoinduced changes is realized after first cycle of IR photoexposure and thermoannealing. We have compared also the different existing models of the photoinduced changes. The results also show that the observed materials have relatively low non-uniformity through the specimen surfaces and can be used as a powerful tool for investigations of picosecond IR laser processes.

Special glassy materials doped with rare-earth elements for fiber optics

Lead-bismuth-gallium-cadmium glasses doped with rare earths elements have been investigated. Certain optical properties of the glasses have been determined. The results of luminescence investiations in the form of absorption and luminescence spectra are presented, and the quantum yields as well as the calculated and measured luminescence lifetimes of the particular rare earths elements in the matrix of the examined glasses have been arranged in the tables. There have been observed extreme luminescence values in the case of particular rare earths elements released to the respective wave lengths. The specific spectral properties of the obtained glasses may find application in optoelectronics and fiber optics.

Halide-chalcogenide glasses for optics and optical fibers

The object of examination were oxygen-free glasses in the system Sb2Se3-KCl-NaF and Sb2Se3-BaCl2- PbCl2. On account of great difficulties connected with passing into the glassy state a special method of synthesizing these glasses has been developed. The glass area in the halide-chalcogenide systems was determined. The characteristic temperatures of glasses and their thermal stability were also determined. Certain properties of the glasses were investigated giving special consideration to producing stable glasses, a few millimeters thick, by using a special method of synthesis. The transmission range of the obtained glasses falls within the limit 0.65 up to 50 micrometers , at the level of 38 to 60%, and the refractive index is: n > 2.5. Material of such properties offers the possibility to obtain optical fibers of very high numerical aperture as well as special application on account of a wide transmission range.