共查询到20条相似文献,搜索用时 31 毫秒
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Li-xun Zhang Yun Liao Zhi-yong Dai Zhong-hua Ou Yong-zhi Liu Zeng-shou Peng 《光电子快报》2006,2(5):345-347
The optical fiber temperature sensoris one of the dis-tributed measurement apparatus applied to the smartstructures of civil and military engineering.In the dis-tributedfiber Ramantemperature sensor ,the anti-Stokesand Stokes scattering radiation is sensi… 相似文献
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ZHANG Zai-xuan WANG Jian-feng LIU Hong-lin XU Hai-fen DAI Bi-zhi LI Chen-xia LI Lan-xiao GENG Dan INSOO S. KIM 《光电子快报》2007,3(6)
A 31 km long range distributed optical fiber Raman photon temperature sensor (DOFRPTS) system have been developed based on temperature effect of the amplified spontaneous Raman scattering in fiber, and using fiber laser as a pumped source. The results show that temperature measuring uncertainty is ±2 ℃, temperature resolution is 0.1 ℃, measurement time is 432 s, spatial resolution is less than 4 m. 相似文献
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In order to meet the high-resolution and wide spectrum range of the backscattering Raman system, this paper designs and builds a Raman test system based on the echelle spectrometer. In the optical splitting system, compared with the ordinary planar grating spectrometer, the use of the echelle improves the resolution of the system without increasing the volume of the system. The use of intensified charge-coupled device (ICCD) in the detection system improves the signal-to-noise ratio (SNR) and the detection limit of weak spectrum. Finally, the Raman system was spectrally calibrated. The broadband backscattering Raman experimental results are given and discussed. The experimental results show that the system has an excellent application prospect for broadband and high-resolution Raman spectrum measurement. 相似文献
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The effect of substrate temperature and ion flux on lattice damage in silicon induced by 1.0 MeV Si ion implantation has been
investigated using Rutherford backscattering channeling (RBSC) and Raman spectroscopy. Over the temperature range of 77–323K,
the temperature dependence of near-surface damage is found to be different from that of end-of-range damage. This may suggest
that different mechanisms for damage growth are dominant along the ion path. The flux effect on damage accumulation varies
with substrate temperatures. Around liquid nitrogen temperature (77K), the near-surface damage decreases with increasing flux,
contrary to the case around room temperature (300K). In the temperature range of ∼ 120–250K, damage is almost independent
of implant flux. Possible causes of the observed phenomena are discussed. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1971,59(12):1644-1663
Three methods of remote air pollution detection-Raman backscattering, resonance backscattering, and resonance absorption-are discussed and compared. Theoretical expressions are derived for the minimum detectable pollutant concentration, and in each case the depth resolution and the problems of interference, pump depletion, and background noise are discussed. A brief discussion of possible laser sources is included, numerical examples of the detectabilities based on present technology are given. The atmospheric transparency limits the useful range to a few kilometers for the Raman and resonance backscattering schemes. For the resonance absorption technique the useful range can be as great as 50 kilometers. 相似文献
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介绍了综合使用瑞利、拉曼、米散射三种技术的激光雷达的基本结构与拉曼散射温度反演原理。对其中的拉曼回波信号进行了背景噪声扣除、滑动平均和小波变换降噪,在此基础上分析了气溶胶对拉曼激光雷达温度廓线反演的影响。利用上述激光雷达信号处理方法对南京上空的温度廓线进行观测,反演了2010年11月19日18时53分至19时35分连续观测的数据。反演的温度廓线表明,观测开始至观测结束,5.5 km处的温度变化为2 K的波动变化;对2010年11月整月的观测数据进行分析处理,得到11月份上中下三旬的平均温度廓线。在10 km高度处,下旬温度比上旬温度低4 K,随着入冬的进程,低空段的大气温度递减率有明显增大的趋势;11月的月平均温度在5~10 km处低于模式值4 K左右,并且两者几乎平行,说明11月份5~10 km各高度温度比模式均低4 K左右。 相似文献
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介绍了一种可用于工作波长在紫外波段的水汽拉曼激光雷达的分光系统,即利用石英三棱镜组合结构实现对激光雷达多波长回波信号的分光。对于266 nm发射波长,由于激光雷达接收的氧气(O2)、氮气(N2)、水汽(H2O)拉曼波长相隔较近,普通的滤光片难以满足要求,利用该分光系统,对其参数尤其是对棱镜间夹角和光束入射角的优化,可将大气中O2、N2、H2O的拉曼散射信号完全分开,使光电检测系统可在三个独立的通道分别接收O2、N2、H2O拉曼信号,从而反演大气中水汽及臭氧含量垂直分布廓线。应用计算机对分光系统进行了模拟计算,以实现分光系统参数的最佳匹配;在入射角约为36°,棱镜间夹角约为106°时,该分光系统可完全分开O2、N2、H2O拉曼信号。最后,用激光激发拉曼管内高压气体产生受激拉曼散射以模拟回波信号波长的实验方法对计算结果进行了验证和标定,结果表明,该分光系统应用于紫外水汽拉曼激光雷达系统具有可靠性和可行性。 相似文献
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Nedeljkovic D. Hauchecorne A. Chanin M.-L. 《Geoscience and Remote Sensing, IEEE Transactions on》1993,31(1):90-101
A lidar method using the anti-Stokes rotational lines of N2 and O2 Raman spectra to determine the temperature of the atmosphere up to 30 km is described. The method uses the variation with the temperature of the envelope of the intensities of the backscattered rotational Raman spectrum. For each temperature of the gas, the ratio of the fluxes through two narrow and close-by filters takes a definite value directly related to the temperature. The difficulty of eliminating the near-by contribution of the Mie backscattering was solved by doubling the filters to produce a rejection factor of 10+8 at the central wavelength. The validity of the method is illustrated by comparing a number of temperature profiles obtained simultaneously with radiosonde and by this new Raman lidar. The theoretical calculation of the method led to an analytic calibration function which, once adjusted with a radiosonde, can provide the temperature on successive days of measurement in the height range of 50 to 25 km 相似文献
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Quaternary Ⅲ-V semiconductor compound In1-xGaxAsyP1-y has recently attracted much attention to the application of various optoelectronic devices. And the lattice dynamics of InGaAsP is also interesting from a physical point of view.We reported a Raman spectra of quaternary InGaAsP epitaxial layers grown on InP over the whole range of composition (0≤y≤1 and 0≤x≤0.47). Raman measurements were performed in the backscattering geometry using a variety of lines of Ar+ laser in the room-temperature and liquid nitrogen temperature ambient. From these measuments, we confirmed that the phonon spectra of InGaAsP exhibited four-mode behaviour of the alloy. We plotted the peak frequencies of the Raman spectra as a function of y (or x), temperature and wavelength of incident light,and also discussed the composition dependence of the peaks intensities. 相似文献
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研究和设计了探测大气CO2浓度的Raman激光雷达,其发射机采用Nd:YAG激光的三倍频354.7 nm作为工作波长,发射的单脉冲能量60 mJ,重复频率20 Hz;接收机采用了光电倍增管(量子效率25%)和光子计数器(计数速率200MHz),探测CO2的Raman散射371.66 nm(频移1285 cm-1)信号,采用组合滤光片来抑制强的354.7 nm Mie-Rayleigh后向散射和氧气Raman后向散射375.4 nm对信号的严重干扰.主要采取排除法,检验其他波段的辐射是否被截止,实验证明回波主要是371.66 nm辐射.O2的干扰大约为CO2信号的1%. 相似文献
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合肥地区夏季臭氧、温度、水汽、气溶胶、二氧化碳测量与对比分析 总被引:1,自引:0,他引:1
为了建立我国的大气模式和制定合适的大气环境保护政策,对大气参数(臭氧浓度,相对湿度,气溶胶后向散射比,温度,二氧化碳浓度等)进行全面测量并分析其基本特性十分重要.多功能性L625激光雷达能够分时测量大气中的臭氧浓度、气溶胶消光系数、散射比、大气温度、二氧化碳混合比、水汽混合比等多种大气参数.对该激光雷达探测的大气参数和其他仪器包括卫星探测器MLS、无线电探空仪、DWL激光雷达、Raman激光雷达进行了对比,验证了L625激光雷达探测结果的可靠性和有效性;并且对测量数据进行了分析,得出了夏季合肥地区臭氧、气溶胶、水汽、温度、二氧化碳的基本特征. 相似文献
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ARL-1 Raman激光雷达系统探测大气二氧化碳 总被引:6,自引:0,他引:6
介绍了中国科学院安徽光学精密机械研究所研制的测量对流层大气二氧化碳的ARI-I Raman激光雷达系统,以Nd:YAG三倍频作为发射光源,接收大气中氮气和二氧化碳的Raman后向散射信号,反演大气中的二氧化碳混合比分布.在ARL-1 Raman激光雷达系统中,设计了测量Raman激光雷达常数的标定装置,实验结果表明,定标光源LED的稳定度可达99.5%.利用该系统对边界层二氧化碳进行了初步定量测量和分析. 相似文献
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大气折射率是影响光电探测领域测量精度的重要因素.为了提高光电测量精度,提出利用纯转动拉曼激光雷达信号反演低层大气折射率廓线的方法.通过接收N2和O2的纯转动拉曼回波信号,由双光栅单色仪分光后获得高低量子信号.根据高低量子信号的比值反演得出大气温度和大气压强廓线,从而获得大气折射指数垂直分布.通过与折射指数理论模型相比较,表明纯转动拉曼激光雷达反演对流层折射指数有较高的精度.给出了多组折射指数廓线的反演结果,得出多天夜晚不同时刻折射指数的特性.结果表明一天中不同时刻折射指数变化较小,7.5 km内最大相对误差约为0.4%;不同月份之间折射指数波动较为明显,4.5 km内相对误差可达3.5%左右. 相似文献
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为了建立我国的大气模式和制定合适的大气环境保护政策,对大气参数(臭 氧浓度,相对湿度,气溶胶后向散射比,温度,二氧化碳浓度等)进行全面测 量并分析其基本特性十分重要。多功能性L625激光雷达能够分时测量大气中 的臭氧浓度、气溶胶消光系数、散射比、大气温度、二氧化碳混合比、水汽混合比 等多种大气参数。 对该激光雷达探测的大气参数和其他仪器包括卫星探测器 MLS、无线电探空仪、DWL激光雷达、Raman 激光雷达进行了对比,验证了L625激光 雷达探测结果的可靠性和有效性;并且对测量数据进行了分析,得出了夏季合肥地 区臭氧、气溶胶、水汽、温度、二氧化碳的基本特征。 相似文献