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The Raman spectrum intensity can be enhanced in liquid core optical fiber (LCOF) of CCl4 solution. We dissolved liquid CC;4 into CS2 and got solutions of different concentrations. There is an optimum concentration at which the maximum Raman intensity can be obtained. There exists an optimum fiber length of 2 m. The experimental result is in good agreement with the theoretical calculation. The Raman intensity becomes powerful with the increase of the pump power and Raman linewidth becomes narrower with the decrease of the CCl4 concentration. 相似文献
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在评述了各种不同类型的聚合物光纤放大器研究的最新进展、基本原理和特点基础上,展望了该器件的应用及其发展前景,并提出了聚合物拉曼光纤放大器这个新的研究方向。 相似文献
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针对连续脉冲编码解码技术在分布式光纤喇曼温度传感器应用中出现被测光纤非线性峰值阀值光功率变低、编码过程较复杂等问题,提出了一种将光脉冲码均匀分布在整条被测光纤的单工循环编码解码技术和应用方案,并在27km单模系统中与传统单脉冲技术系统做了对比实验.结果表明:相比连续编码解码技术,单工循环编码解码技术不仅保持了编码解码技术相对于传统单脉冲技术的信噪比改善能力,而且有效地提高了光纤的非线性峰值阀值光功率.在编码时只需循环发送一组码,就可使系统的信噪比和测量距离获得极大的提高.采用211位循环编码解码技术的多模系统经16万次重复测量后,可在25km处获得±1.5℃的温度不确定度,空间分辨率为3m. 相似文献
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GaInN light-emitting diodes with omni-directional reflector using nanoporous SnO_2 film 总被引:1,自引:1,他引:1
Enhancement of light extraction in a GaInN light-emitting diode (LED) employing an omni-directional reflector (ODR) consisting of GaN, SnO2 nanorod and an Ag layer was presented. The ODR comprises a transparent, quarterwave layer of SnO2 nanorod claded by silver and serves as an ohmic contact to p-type GaN. Transparent SnO2 sols were obtained by sol-gel method from SnCl2·2H2O, and SnO2 thin films were prepared by dip-coating technique. The average size of the spherical SnO2 particles obtained is 200 nm. The refractive index of the nanorod SnO2 film layer is 2.01. The GaInN LEDs with GaN/SnO2/Ag ODR show a lower forward voltage. This was attributed to the enhanced reflectivity of the ODR that employs the nanorod SnO2 film layer. Experimental results show that ODR-LEDs have lower optical losses and higher extraction efficiency as compared to conventional LEDs with Ni/Au contacts and conventional LEDs employing a distributed Bragg reflector (DBR). 相似文献
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针对太赫兹扫描成像设备存在的图像清晰度差、边缘模糊等问题,提出了一种基于生成对抗网络的太赫兹图像超分辨率重建算法。首先,在处理太赫兹图像时引入限制对比度自适应直方图均衡方法,有效解决了太赫兹图像对比度低的问题;其次,在生成对抗网络的基础上,提出了一种基于增强注意力机制的残差生成对抗网络,实现了太赫兹扫描图像的超分辨率重建,提升了图像纹理和细节的重建能力;最后利用频谱归一化的U-net网络对生成器生成的重建图像进行判别,增强了训练的稳定性。实验结果表明,提出的太赫兹图像超分辨率重建算法将太赫兹线阵相机所成太赫兹图像的边缘强度提高了7%,峰值信噪比提高了13%,平均梯度提高了12%,结构相似度提高了14%,验证了该算法的优越性和有效性。 相似文献