Bismuth-doped zinc aluminosilicate glasses and glass-ceramics with ultra-broadband infrared luminescence

Abstract Broadband infrared luminescence covering the optical telecommunication wavelength region of O, E and S bands was observed from bismuth-doped zinc aluminosilicate glasses and glass-ceramics. The spectroscopic properties of the glasses and glass-ceramics depend on the thermal-treatment history. With the appearance of gahnite (ZnAl 2 O 4 ) crystalline phase, the fluorescent peak moves to longer wavelength, but the fluorescent intensity decreases. The $1300 nm fluorescence with a FWHM larger than 250 nm and a lifetime longer than 600 ls possesses these optical materials with potential applications in laser devices and broadband amplifiers. The broad infrared luminescence from the bismuth-doped zinc aluminosilicate glasses and glass-ceramics might be from BiO or bismuth clusters rather than from Bi 5+ and Bi 3+

Exciton spectra of SnO 2 nanocrystals with surficial dipole layer

Abstract Experimental results of absorption, luminescence and excitation spectra in both bare and coated SnO 2 nanocrystals are given. It is found that when the SnO 2 nanocrystals are coated by a layer of organic moleculae, the absorption edge shifts to the longer wavelength direction as the particle size decreases, which is inconsistent with that of bare SnO 2 nanocrystals. It is demonstrated that the size and surface situations of nanocrystals have great influence on their spectroscopic properties. The experimental data are discussed in terms of the quantum confinement effects and dielectric confinement effects

Investigations on bismuth and aluminum co-doped germanium oxide glasses for ultra-broadband optical amplification

Abstract The broadband luminescence covering 1.2-1.6 lm was observed from bismuth and aluminum co-doped germanium oxide glasses pumped by 808 nm laser at room temperature. The spectroscopic properties of GeO 2 :Bi,Al glasses strongly depend on the glass compositions and the pumping sources. To a certain extent, the Al 3+ ions play as dispersing reagent for the infrared-emission centers in the GeO 2 :Bi,Al glasses. The broad infrared luminescence with a full width at half maximum larger than 200 nm and a lifetime longer than 200 ls possesses these glasses with the potential applications in broadly tunable laser sources and ultra-broadband fiber amplifiers in optical communication field