Petr Kostka

Heavy metal oxide glasses: preparation and physical properties

Abstract Heavy metal oxide glasses have been investigated in the following systems: TeO2–PbO–PbCl2, TeO2–ZnO, Ga2O3–PbO–Bi2O3 glasses with low OH concentration were prepared. The influence of the processing conditions on the color, the structure and the optical properties of the prepared samples was also assessed. Mixtures of starting oxides were melted in various reactive conditions using Pt, Au, SiO2 and alumina crucibles. A set of physical measurements including chemical and X-ray analysis, scanning electron microscopy, absorption spectroscopy, ultraviolet and infrared absorption edges and thermo-physical properties, were carried out. Samples were doped with Nd, Pr and Er rare earth ions. Low temperature photoluminescence spectra show the expected rare earth transitions and the broad band emission of the base glass.

Preparation and characterization of sulfide, selenide and telluride glasses

Abstract Chalcogenide glass systems As–S, As–Se, As–S–Se and Ge–Se–Te and those doped with rare-earth (RE) elements have been prepared and characterized by absorption spectroscopy, scanning electron microscopy and low-temperature photoluminescence. Photoluminescence spectra have been measured over a wide temperature range and the role of multi-phonon transitions in mediating the inner 4f–4f electronic transitions of excited RE3+ ions was demonstrated. A peculiar Pr related band at 1600 nm has been found in some samples. The shift of the dominant luminescence band to higher energies with increasing temperature has been observed. Both position and line width of the luminescence band are not strongly temperature dependent at lower temperatures but considerable dependence appears when room temperature is approached.

Optical fibers of As2S3 glasses: preparation and characterization

Chalcogenide glasses based on arsenic sulfide (As2S3), arsenic selenide or telluride are known to exhibit high optical nonlinearities which are necessary for advanced applications in telecommunications. Both, standard optical fibers and microstructured fibers have been fabricated from chalcogenide glasses. In this paper we deal with As2S3 solid core fibers and capillary fibers coated with a polymer jacket of UV acrylate. The guiding mechanism employing the reflection on boundary of high-index glass (a refractive index of about 2.4) and hollow cavity (n=1) was confirmed by ray-optic calculations. Fibers were drawn from input As2S3 rods and tubes. The rods were prepared from extra pure arsenic and sulfur by their melting in an evacuated ampoule. The tubes were prepared by using rotational melting technique in an evacuated ampoule rotating at 1600 rpm. Rods and tubes were elongated into fibers by using a fiber drawing facilities for preparation of optical fibers from soft optical glasses. Temperatures in a range 300-400 °C and drawing velocities of about 0.1 m/s were used. Fibers were prepared either without any polymeric jacket or they were provided by a jacket of UV acrylate (n ∼ 1.5). Fibers with diameters from 0.2 to 0.4 mm were fabricated. Dimensions of prepared fibers were measured by optical microscopy without prior polishing. Transmission properties of prepared fibers were characterized by measuring angular distributions of output power at the wavelength of 670 nm. Optical losses of fibers exceeding 2 dB/m were determined by using the cut back method.

Optical fibers of As 2 S 3 glasses: preparation and characterization

Chalcogenide glasses based on arsenic sulfide (As2S3), arsenic selenide or telluride are known to exhibit high optical nonlinearities which are necessary for advanced applications in telecommunications. Both, standard optical fibers and microstructured fibers have been fabricated from chalcogenide glasses. In this paper we deal with As2S3 solid core fibers and capillary fibers coated with a polymer jacket of UV acrylate. The guiding mechanism employing the reflection on boundary of high-index glass (a refractive index of about 2.4) and hollow cavity (n=1) was confirmed by ray-optic calculations. Fibers were drawn from input As2S3 rods and tubes. The rods were prepared from extra pure arsenic and sulfur by their melting in an evacuated ampoule. The tubes were prepared by using rotational melting technique in an evacuated ampoule rotating at 1600 rpm. Rods and tubes were elongated into fibers by using a fiber drawing facilities for preparation of optical fibers from soft optical glasses. Temperatures in a range 300-400 °C and drawing velocities of about 0.1 m/s were used. Fibers were prepared either without any polymeric jacket or they were provided by a jacket of UV acrylate (n ∼ 1.5). Fibers with diameters from 0.2 to 0.4 mm were fabricated. Dimensions of prepared fibers were measured by optical microscopy without prior polishing. Transmission properties of prepared fibers were characterized by measuring angular distributions of output power at the wavelength of 670 nm. Optical losses of fibers exceeding 2 dB/m were determined by using the cut back method.

Optical fibers of As2S3glasses: preparation and characterization

Chalcogenide glasses based on arsenic sulfide (As2S3), arsenic selenide or telluride are known to exhibit high optical nonlinearities which are necessary for advanced applications in telecommunications. Both, standard optical fibers and microstructured fibers have been fabricated from chalcogenide glasses. In this paper we deal with As2S3 solid core fibers and capillary fibers coated with a polymer jacket of UV acrylate. The guiding mechanism employing the reflection on boundary of high-index glass (a refractive index of about 2.4) and hollow cavity (n=1) was confirmed by ray-optic calculations. Fibers were drawn from input As2S3 rods and tubes. The rods were prepared from extra pure arsenic and sulfur by their melting in an evacuated ampoule. The tubes were prepared by using rotational melting technique in an evacuated ampoule rotating at 1600 rpm. Rods and tubes were elongated into fibers by using a fiber drawing facilities for preparation of optical fibers from soft optical glasses. Temperatures in a range 300-400 °C and drawing velocities of about 0.1 m/s were used. Fibers were prepared either without any polymeric jacket or they were provided by a jacket of UV acrylate (n ∼ 1.5). Fibers with diameters from 0.2 to 0.4 mm were fabricated. Dimensions of prepared fibers were measured by optical microscopy without prior polishing. Transmission properties of prepared fibers were characterized by measuring angular distributions of output power at the wavelength of 670 nm. Optical losses of fibers exceeding 2 dB/m were determined by using the cut back method.