In this work, we have studied the concentration quenching in transparent glass ceramics containing Er^3＋：NaYF4 nanocrystals. For different concentrations, the emission spectra and decay curves of the ^4I/3/2 → ^4I1...In this work, we have studied the concentration quenching in transparent glass ceramics containing Er^3＋：NaYF4 nanocrystals. For different concentrations, the emission spectra and decay curves of the ^4I/3/2 → ^4I15/2 emission were measured. The Er-concentration dependence of integrated intensity and lifetime of ^4I13/2→^4I15/2 emission are showed. With the increase of the Er^3＋ doping concentration, the 1.5 μm fluorescence emission first increases, then decreases, and the lifetime falls gradually. With 980 nm excitation, the efficiency of the energy transfer from Er^3＋ to quenching centers reaches 73.73% for the sample with 4 mol% Er^3＋. Meanwhile, owing to the relation of fluorescence integrated intensity and Er-concentration, a dipole-dipole quenching mechanism in the framework of a limited diffusion regime has been proved. Using the limited diffusion case, the critical concentration for quenching has been determined from a fitting equation of the lifetime and Er-concentration. The fit- ting result shows the critical concentration for quenching is higher than the values obtained in Er-doped different glass by an order of magnitude.展开更多
A novel process for fabricating high-density and high diffraction efficiency inor- ganic gratings has been proposed by combining laser interference and chemical etching. In the present work, UV photosensitive Zr-conta...A novel process for fabricating high-density and high diffraction efficiency inor- ganic gratings has been proposed by combining laser interference and chemical etching. In the present work, UV photosensitive Zr-contained sol was synthesized, and photosensitive ZrO2/BzAc gel films on (100) silicon were prepared using the sol-gel method. Subsequently, inorganic film gratings with a pitch of 1 μm were fabricated by laser interference in this photosensitive gel film combining with the process of heat treatment. In order to increase the depth-to-width ratio of the grat- ings, chemical etching was adopted by using iodine-saturated KOH as anisotropic etchant, which improved the diffraction efficiency of the gratings effectively. Fur- thermore, the diffraction efficiency was improved by gold coating to enhance the surface glossiness and reflection coefficient.展开更多
基金supported by the Fujian Natural Science Foundation of China (Grant No. 2009J05139)the Fujian Science and Technology major projects of China (Grant No. 2007HJ0004-2)+1 种基金the Project of Education Department of Fujian Province of China (Grant No. JK2011008)the Innovation Project for Young Scientists of Fujian Province of China (Grant No. 2007F3027)
文摘In this work, we have studied the concentration quenching in transparent glass ceramics containing Er^3＋：NaYF4 nanocrystals. For different concentrations, the emission spectra and decay curves of the ^4I/3/2 → ^4I15/2 emission were measured. The Er-concentration dependence of integrated intensity and lifetime of ^4I13/2→^4I15/2 emission are showed. With the increase of the Er^3＋ doping concentration, the 1.5 μm fluorescence emission first increases, then decreases, and the lifetime falls gradually. With 980 nm excitation, the efficiency of the energy transfer from Er^3＋ to quenching centers reaches 73.73% for the sample with 4 mol% Er^3＋. Meanwhile, owing to the relation of fluorescence integrated intensity and Er-concentration, a dipole-dipole quenching mechanism in the framework of a limited diffusion regime has been proved. Using the limited diffusion case, the critical concentration for quenching has been determined from a fitting equation of the lifetime and Er-concentration. The fit- ting result shows the critical concentration for quenching is higher than the values obtained in Er-doped different glass by an order of magnitude.
基金the National Natural Science Foundation of China (Grant No. 90401009) the Xi’an Applied Materials Innovation Fund (Grant No. XA-AM-200611)
文摘A novel process for fabricating high-density and high diffraction efficiency inor- ganic gratings has been proposed by combining laser interference and chemical etching. In the present work, UV photosensitive Zr-contained sol was synthesized, and photosensitive ZrO2/BzAc gel films on (100) silicon were prepared using the sol-gel method. Subsequently, inorganic film gratings with a pitch of 1 μm were fabricated by laser interference in this photosensitive gel film combining with the process of heat treatment. In order to increase the depth-to-width ratio of the grat- ings, chemical etching was adopted by using iodine-saturated KOH as anisotropic etchant, which improved the diffraction efficiency of the gratings effectively. Fur- thermore, the diffraction efficiency was improved by gold coating to enhance the surface glossiness and reflection coefficient.
