Papers by Keyword: Stimulated Emission

Abstract: High yield ZnO nanorods are synthesized by a simple wet chemical method. The crystal morphology and structure of the ZnO nanorods are examined by transmission electron microscopy (TEM) and X-Ray Diffraction (XRD), respectively. The properties of the excitonic luminescence are investigated by temperature dependent photoluminescence (PL) spectra. Barely observed visible emission band indicates the good optical quality of the ZnO nanorods and the abnormal position and intensity changes of the emission peaks indicates the localization property of exciton.

Abstract: Stimulated emission and optical gain problems are reviewed on the basis of analysis of highly photoexcited III-Nitride and ZnO wide-gap materials. Spontaneous and stimulated emission along with optical gain of these materials in UV region is analyzed. The possible mechanisms of inverted population in In-containing materials and ZnO semiconductors are discussed involving mechanisms of dense electron-hole plasma, carrier (exciton) localization, as well as various interaction processes in dense exciton gas.

Abstract: Optical characterization of molecular-beam-epitaxy-grown ZnO and MgZnO epitaxial layers on sapphire (0001) substrates is presented. The parameters such as carrier recombination time and optical gain coefficient are analyzed. Radiative recombination mechanisms of ZnO in dense quasiparticle system are discussed. The ZnO epilayers even with lower structural quality are tolerable for applications in optoelectronics as light emitters.

Abstract: The little disturbance theory in quantum mechanics was used to research the frequency and the high emissivity of far infrared emission from natural black tourmaline on basis of the electric dipole model. Comparing the theoritical and the experimental value of the frequency we found that they are in match case. So we testified that the tourmaline partical is really composed of lots of crystal electric dipole. At the same time we explained the curves of infrared absorption analysis of natural black tourmalines at room temperature are simillar despite of their diversification in chemistry component and producing area, and they have high infrared emissivity from the theory point of view. Finally we pointed out the condition under which the high infrared emissivity of tourmaline can be obtained theoritically.