共查询到19条相似文献,搜索用时 109 毫秒
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随着激光技术的最新发展,钛宝石激光系统产生了极强的超短光脉冲。目前,光谱展宽和超宽带色散的新技术,可将脉冲压缩到低于5fs,并具有几千兆瓦的峰值功率。这些是迄今为止获得的最短高功率脉冲。它们开启了在光波周期的时间范畴内控制不受到扰动的光与物质相互作用的研究途径,并且可能应用在“水窗”(wate-window)中产生相干X光以及产生阿秒软X光脉冲。自激光锁模技术发明以来,超短光脉冲技术一直是人们不断研究的课题,最终于80年代中期,在620urn波长取得了三个光波周期的6fs脉冲。这种从未有过的窄脉宽是通过压缩复杂染料激光… 相似文献
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为了提升激光技术在色素性疾病治疗等生物医学应用效果, 研制了一种1064nm, 532nm, 570nm三波长激光器。采用电光调Q Nd:YAG激光器获得最窄脉宽为11ns的1064nm脉冲激光输出, 使用磷酸氧钛钾(KTP)非线性晶体对基频光腔外倍频获得532nm激光输出; 以固体染料块为激光增益介质, 倍频光为抽运光, 可获得中心波长为570nm的黄光输出, 光光转换效率为61.3%。结果表明, 通过改变氙灯注入电压, 可以调节1064nm激光脉冲输出特性; 增加固体染料激光器腔长, 可以调节染料激光输出光谱特性。该研究结果对激光器灵活应用具有重要意义。 相似文献
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本文研究了在平面态和场致向列相之间快速切换的聚合物稳定胆甾相(PSCT)液晶光阀的彩色显示。采用紫外光诱导相分离法(PIPS)制备具有染料掺杂的聚合物稳定胆甾相液晶光阀,通过3种染料在可见光区的吸收作用,对入射白光进行选择性吸收过滤,得到不同颜色的出射光。结果表明:当PSCT处在平面态下,分子螺旋排列,染料对入射光波的吸收不受光波偏振方向的影响,器件具有很强的吸收作用,呈现有色态;当处于场致向列相,染料的吸收作用微小,器件呈透明态,因此器件具有一定的对比度,且不需要偏振片;器件在平面态和场致向列相之间快速切换的响应时间短于7ms。PSCT光阀可以用作滤色器,在多种染料的共同作用下,快速选择滤色得到多种彩色可见光,组成彩色显示平面。 相似文献
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一、染料激光器:1.利用Nd:YAG激光泵浦的一种同步锁模染料激光器的非线性混合,放大和微微秒脉冲产生2.横向流动闪光灯泵浦染料激光器3.高功率染料激光器二、一般应用:1.利用光合成和塑料闪烁器的微微秒脉冲研究条纹相机2.高速辐射相机,利用一种脉冲横向模红宝石激光器和水合电子吸收现象3.激光手术应用4.可调激光器-生物学探头 相似文献
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推导了准稳态下横向抽运的脉冲染料激光放大器的简化速率方程,提出了双侧横向抽运方式的脉冲染料激光放大器的设计原则和设计方法.应用高功率脉冲染料激光放大器的物理设计结果,研制了输出功率为50 W的脉冲染料激光放大器的实验装置.采用铜蒸气激光(CVL)作为抽运光,在此染料激光放大器上进行了实验研究,获得染料激光输出功率为52 W,抽运激光功率提取效率为41%.给出了染料激光波长、注入染料激光功率以及抽运激光的时间和空间匹配特性与染料激光放大器输出激光功率和抽运激光功率提取效率的相互关系,讨论了染料溶液浓度对双侧横向抽运方式的脉冲染料激光放大器的输出光束质量的影响. 相似文献
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当强光脉冲和吸收染料相互作用时,染料中将产生大量的激发态分子从而降低了基态吸收。如果光脉冲宽度△t_L比荧光寿命τ_F短而且激发态的吸收可以忽略时,染料激发态的分子数就等于吸收光子数。此时,吸收染料介质可作为光子计数器。皮秒光脉冲能量可由测量光脉冲通过染料样品的能量透射率T_E来决定。用这种办法可校正光电探测器的绝对皮秒脉冲能量,当测量了能量透射率和输入峰值光强时,便可用简单公式计算脉冲宽度,因而这为皮秒 相似文献
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Steven S. Hegedus Ruhi Kaplan 《Progress in Photovoltaics: Research and Applications》2002,10(4):257-269
The effect of i-layer thickness, tin oxide texture, and back reflector (BR) on optical enhancement has been systematically studied in a series of 20 a-Si p–i–n solar cells. The internal quantum efficiency has been analyzed by a simple model based on the work of Schade and Smith. The enhancement of optical absorption is characterized by m, a wavelength-dependent fitting parameter representing the increase in optical pathlength relative to the i-layer thickness d. Solar cells with an Al BR have negligible optical enhancement, with m < 1.5, consistent with large parasitic absorption at the Al/Si interface as reported by others. Solar cells on highly textured SnO2 with ZnO/Al or ZnO/Ag BR have peak values of m ∼ 3–4, with ZnO/Ag having slightly larger values than ZnO/Al. It was found that m has a strong dependence on the product αd, and that maximum values of m increase with reflectivity of the BR. It is shown that a major source of parasitic absorption loss at long wavelengths is light trapping in the textured SnO2 front contact. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Drawing-induced paramagnetic defects (E'centers and oxygen-associated hole centers (OHCs)) and optical absorption bands at 630 nm and in the UV region are investigated for optical fibers. These fibers are drawn from pure silica glass preforms consolidated in atmospheres containing O2 and Cl2. UV absorption bands at 245 nm and 275 nm are clearly observed through deconvolution of the absorption spectra of optical fibers. The defects and absorption bands are influenced by the atmosphere in the consolidation process: (1) the OHCs and the absorption bands at 630 nm and 275 nm increase the intensity with increasing O2 content and with decreasing Cl 2 content; (2) the E' centers decrease under the same conditions; and (3) the absorption band at 245 nm is independent of the atmosphere 相似文献
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借助紫外可见光谱仪观测和电子结构计算,研究了紫外光照对偶氮香蕉型液晶电子结构和光吸收特性的影响。吸收光谱显示:这种液晶的两个光学吸收峰分别位于360nm和275 nm。电子结构计算表明:这两个光学吸收主要来自于液晶中含偶氮官能团的电子跃迁。结果表明:365nm光子可将液晶中的氮氮双键打断,从而导致其在360nm处的吸收迅速降低,同时使275 nm处的吸收相应增加。 相似文献
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Optical Path Length,Temperature, and Wavelength Effects Simulation on Ozone Gas Absorption Cross Sections towards Green Communications
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Michael David Mohd Haniff Ibrahim Sevia Mahdaliza Idrus Nor Hafizah Ngajikin Asrul Izam Azmi Tay Ching En Marcus 《电子科技学刊:英文版》2016,14(3):199-204
Ozone is a green house gas. Ozone absorption cross sections have been reported with discrepancies and inconsistencies. In this paper, simultaneous effects of the optical path length and temperature variations on ozone gas absorption cross sections are investigated at different wavelengths. HITRAN 2012, the latest available line list on spectralcalc.com simulator, is used in this study to simulate ozone gas absorption cross sections in relation to the simultaneous effects of the optical path length and temperature at the wavelengths of 603 nm and 575 nm. Results obtained for gas cells with the optical path length from 10 cm to 120 cm show that the decrease in temperatures from 313 K to 103 K results in the increase in ozone gas absorption cross sections. At wavelengths of 603 nm and 575 nm, the percentage increase of ozone gas absorption cross sections is 1.22% and 0.71%, respectively. Results obtained in this study show that in the visible spectrum, at constant pressure, ozone gas absorption cross sections are dependent on the temperature and wavelength but do not depend on the optical path length. Analysis in this work addresses discrepancies in ozone gas absorption cross sections in relation to the temperature in the visible spectrum; thus, the results can be applied to get optimal configuration of high accuracy ozone gas sensors. 相似文献
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利用YAG激光器二倍频 5 32nm连续激光作为记录光 ,连续单色光作为读出光 ,在细菌视紫红质 (BRD96N)材料上进行了图像写 /读实验。通过理论分析BRD96N膜所记录的图像对比度随读出光波长变化趋势 ,得到图像对比度变化曲线 ,并通过实验方法验证。实验结果表明 ,在BRD96N膜基态峰 (5 70nm)附近 5 5 0nm波长处 ,可获得最佳的图像对比度 (~ 1 6 3∶1) ;在亚稳态 (M态 )吸收带内 (390~ 4 5 0nm) ,图像出现反转现象 相似文献