Optical amplification near 1300 nm in bismuth-doped strontium germanate glass

We demonstrate the broadband optical amplification in bismuth-doped strontium germanate glass with 808 nm and 980 nm laser diodes (LDs) as excitation sources. The net optical gain has been obtained within the wavelength region of 1272 to 1348 nm with 808 nm laser diode under 0.97 W power. The maximum gain and gain coefficients are 1.23 and 1.03 cm(-1) at 1315 nm, respectively. The signal increment at 1300 nm is 2.8 times with 980 nm LD, under 3 W power. The differential thermal analysis measurement reveals the good thermal stability of the studied glass. This glass could be suggested as a promising gain medium for broadband optical amplifiers.

Broadband optical amplification near 1300 nm in bismuth-doped germanate glass

In this paper, we present the broadband optical amplification in bismuth-doped germanate glass, at the second telecommunication window when excited with 808 nm and 980 nm laser diodes, respectively. The amplification range is from 1272 nm to 1348 nm wavelength, which is within the O-band of silica fiber communication. This bismuth-doped glass can be used as ultra broadband amplification material for wavelength-division-multiplexing (WDM) at the second telecommunication window.

Blue-yellow ZnO homostructural light-emitting diode realized by metalorganic chemical vapor deposition technique

We report on the realization of ZnO homojunction light-emitting diodes (LEDs) fabricated by metalorganic chemical vapor deposition on (0001) ZnO bulk substrate. The p-type ZnO epilayer was formed by nitrogen incorporation using N2O gas as oxidizing and doping sources. Distinct electroluminescence (EL) emissions in the blue and yellow regions were observed at room temperature by the naked eye under forward bias. The EL peak energy coincided with the photoluminescence peak energy of the ZnO epilayer, suggesting that the EL emissions emerge from the ZnO epilayer. In addition, the current-voltage and light output-voltage characteristics of ZnO homojunction LEDs have also been studied. (c) 2006 American Institute of Physics.

Structural and optical properties of nonpolar m-plane GaN and GaN-based LEDs on gamma-LiAlO2

We report the structural and optical properties of nonpolar m-plane GaN and GaN-based LEDs grown by MOCVD on a gamma-LiAlO2 (100) substrate. The TMGa, TMIn and NH3 are used as sources of Ga, In and N, respectively. The structural and surface properties of the epilayers are characterized by x-ray diffraction, polarized Raman scattering and atomic force microscopy (AFM). The films have a very smooth surface with rms roughness as low as 2nm for an area of 10 x 10 mu m(2) by AFM scan area. The XRD spectra show that the materials grown on gamma-LiAlO2 (100) have < 1 - 100 > m-plane orientation. The EL spectra of the m-plane InGaN/GaN multiple quantum wells LEDs are shown. This demonstrates that our nonpolar LED structure grown on the gamma-LiAlO2 substrate is indeed free of internal electric field. The current voltage characteristics of these LEDs show the rectifying behaviour with a turn on voltage of 1-3 V.

Continuous-wave and passively mode-locked Yb : GYSO lasers pumped by diode lasers

We report both continuous-wave and passively mode-locked laser actions in a Yb3+-doped gadolinium yttrium oxyorthosilicate Yb:GdySiO(5) (Yb:GYSO) crystal. Continuous-wave (CW) laser operations were compared under different pump conditions with high-power diodes of different wavelengths and fiber cores. CW mode-locking was obtained with a semiconductor saturable absorber mirror.

吡唑啉衍生物有机电致发光器件中激基复合物的发射

以两种吡唑啉衍生物为空穴传输材料(HTM)和BBOT为电子传输材料组成双层器件，获得了相对于组成材料的荧光光谱红移和宽化的电致发光．双层器件和HTM：BBOT等摩尔混蒸薄膜的光致发光及电致发光测量表明，该谱带来自HTM／BBOT界面激基复合物的发射，根据器件的能级图，激基复合物的类型为BBOT的激发态BBOT^