排序方式: 共有14条查询结果,搜索用时 46 毫秒
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用传统的高温熔融法熔制了一系列掺Er硅酸盐玻璃, 并测试了这些样品经5 kGy γ 射线辐照前后紫外至近红外的吸收和荧光光谱. 实验结果表明, 辐致暗化效应使得玻璃材料中形成了大量色心, 导致在400 nm附近出现强吸收带, 其尾端延伸至近红外区. 辐照产生的新能带增加了基质与Er3+ 特定能级(如2H11/2, 4S3/2及4F9/2等) 之间的能量传递, 从而使辐照后的样品荧光寿命减小, 且在相同激发条件下荧光强度下降. 室温下辐照样品在荧光测试过程中出现了漂白现象. 相似文献
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We report the space-selective formation of colour centres and refractive index change in LiF crystals at room temperature by an 800nm Ti:sapphire femtosecond laser irradiation. Optical absorption and photoluminescence spectra have been measured for the crystal before and after the laser irradiation. The absorption spectra indicate F and F3^ colour centres are induced in LiF after the laser irradiation. When the temperature of heat treatment reaches 300℃, the absorption peak disappears, indicating that the induced colour centres are bleached. The induced refractive index change is also evaluated. A mechanism for the formation of colour centres and refractive index change is proposed. 相似文献
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用改进的化学气相沉积方法和溶液掺杂方法制备了掺Bi双包层石英基光纤. 测试了掺Bi光纤预制棒切片的吸收光谱和掺Bi光纤在特定波长下的吸收系数,在不同波长的激光激发下, 研究了掺Bi光纤的近红外荧光光谱. 掺Bi光纤在976 nm激光激发下,其荧光光谱范围在1000---1400 nm之间, 荧光峰的峰值位于1140 nm附近,半高宽约为130 nm;在793和808 nm激光激发下得到了 1000---1700 nm的超宽带近红外荧光,半高宽超过250 nm.通过对掺Bi光纤预制棒切片进行900 ℃ 保温1 h的热处理后,发现在808 nm激光 激发下预制棒切片的荧光强度增加了近4倍.研究结果表明,具有超宽带荧光特性的双包层掺Bi光纤 有望作为超短脉冲激光器和可调谐激光器的增益介质. 相似文献
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We provide a novel hollow-core holey fibre that owns a random distribution of air holes in the cladding. Our experiments demonstrate that many of the features previously attributed to photonic crystal fibres with perfect arrangement of air holes, in particular, photonic bandgap guidance, can also be obtained in the fibre. Additionally, this fibre exhibits a second guided mode with both the two-lobe patterns, and each pattern is in different colour. 相似文献
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We prepare bismuth-doped borosilicate glasses and the luminescence properties in infrared wavelength region are investigated. Transmission spectrum, fluorescence spectrum and fluorescence decay curve are measured. The glasses exhibit a broad infrared luminescence peaking at 1340nm with the full width at half maximum of about 205 nm, and lifetime of 273us when excited by an 808-nm laser diode. The glasses are promising materials for broadband optical amplifiers and tunable lasers. 相似文献
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We report on the fabrication of two kinds of large core arca Nd^3 doped sillcate glass photonic crystal fibres and demonstration of the fibre waveguiding properties the measured minimum loss of one kind of fibres is 2。5db/m at 660 nm.The fibres sustain only a single mode at least over the wavelength range from 660nm to 980 nm. 相似文献
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Transparent Ni^2+-Doped MgO-Al2O3-SiO2 Glass Ceramics with Broadband Infrared Luminescence 下载免费PDF全文
We report on transparent Ni^2+-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence. Ni^2+-doped MgO-Al2O3-SiO2 glass is prepared by using the conventional method. After heat treatment at high temperature, MgAl2O4 crystallites are precipitated, and their average size is about 4.3 nm. No luminescence is detected in the as-prepared glass sample, while broadband infrared luminescence centred at around 1315 nm with full width at half maximum (FWHM) of about 300 nm is observed from the glass ceramics. The observed infrared emission could be attributed to the ^3T2g(^3F)→^3A2g(^3F) transition of octahedral Ni^2+ ions in the MgAl2O4 crystallites of the transparent glass ceramics. The product of the fluorescence lifetime and the stimulated emission cross section is about 1.6×10^-24 s cm^2. 相似文献
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