共查询到18条相似文献,搜索用时 93 毫秒
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根据惯性约束聚变系统技术要求,提出了镀膜减反方案,以解决现有光栅由于元件表面反射影响零级透过率的问题。使用严格耦合波理论分析了镀sol-gel减反膜的取样光栅特性,详细地分析了仿形膜和平面膜的减反情况和取样效率的变化。结果发现,镀平面膜是一种可行的技术方案,光栅表面反射几乎完全消除,表明可以通过取样光栅镀膜减反来达到提高透射率的目的;裸光栅的深度为12 nm时,平面减反膜厚为60 nm,即光学厚度为等效1/4波长:72 nm。此时的透射率为99.8%,取样效率为0.241‰。 相似文献
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运用时域有限差分方法,研究了光栅减反层结构对太阳能电池光电转换效率及储能效果的影响.具体从光栅形状、高度以及光栅表面金属薄膜厚度出发.结果表明经光栅减反层优化表面结构的太阳能电池的光电转换效率显著增大,储能效果大大得到提升.尤其是三角形光栅太阳能电池.随着镀层厚度的增加,储能效果增加,但当薄膜厚度过厚时,储能效果反而降低. 相似文献
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《中国光学与应用光学文摘》2005,(2)
TB43 2005021300 用耦合波法分析平面镀膜分频光栅的特性=Coupled-wave analysis of color separation grating with planarizing AR coating[刊,中]/杨春林(成都精密光学工程研究中心.四 川,成都(610041)),许乔…//光子学报.-2004,33 (6).-751-754 使用严格的耦合波理论分析了ICF系统的色分离光 栅(CSG)特性,特别针对平面镀膜减反后的情况进行了详 相似文献
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《大学物理》2020,(8)
薄膜干涉是大学物理波动光学教学的重要内容,也是薄膜光学的理论基础.薄膜干涉的一个重要应用是用于设计减反膜和高反膜.本文基于传输矩阵法,定量计算了多层介质膜的反射率.以BK7玻璃为例,无镀膜时在可见光范围内,其反射率约为4%.利用薄膜的相消干涉可以减少表面的反射率.镀一层减反膜时,对设计波长550 nm其反射率下降为1.3%,一旦偏离设计波长减反效果变差;镀两层减反膜时,在470 nm~670 nm范围内,减反效果明显改善,反射率均低于1.3%.利用薄膜的相长干涉可以增加表面的反射率.以熔石英为例,镀一层薄膜时,对设计波长1500 nm其反射率可由未镀膜时的3.3%提高到30%;镀七组薄膜时在1360 nm~1660 nm范围内其反射率均可达99%以上.通过这些定量计算,让学生更加深刻地理解所学理论知识在实际中的应用,培养工程意识,提高学习兴趣. 相似文献
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本文根据等效界面和等效光纳概念,推导出宽带减反膜的减反射限定公式。研究表明,按限定公式确定的折射率参数可有效地进行规整膜厚的三层宽带减反膜设计。 相似文献
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《Photonics and Nanostructures》2014,12(5):493-500
Solar cell nano-structured anti-reflection coatings based on graded index (GI) and mode coupling are all proposed to significantly reduce the reflection from semiconductor–air interface. In this work, it is shown that purely graded index approach can lead to degradation of long wavelength absorption by eliminating quasi-guided mode excitation. The reason is that the physically graded layer not only provides low reflectance path from air to semiconductor, but also from semiconductor to air, leading to photon escape. This results in out-coupling of photons from the semiconductor to air. On the other hand, anti-reflection coating based on mode coupling does not suffer from degraded long wavelength absorption and it is capable of acting as one-way photon pass coating. It is found that the sidewall thickness of mode coupling anti-reflection coating has significant impact on its effectiveness for anti-reflection, and therefore the selection of process methods is critical for its low reflectance. It is proposed that the purely graded index coating is more suitable for wafer-based photovoltaics where full absorption is possible by two photon traces. The mode coupling coating is suitable for both wafer-based photovoltaics and thin-film photovoltaics since it provides not only low reflectance but also long wavelength quasi-guided mode excitations. In the end, new types of anti-reflection coating and light trapping structure are proposed to further enhance the performance. 相似文献
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本文以我厂生产的长焦距镜头为例,介绍了满足彩色还原特性的长焦距镜头增速膜的设计思想,设计方法和结果。这种具有彩色还原性能的镜头现已批量生产。 相似文献
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Influence of Phase-Shift on Side-Mode Suppression Ratio in Fiber Grating External Cavity Semiconductor Lasers 总被引:2,自引:0,他引:2
He Xiaoying Huang Dexiu Li Wei 《International Journal of Infrared and Millimeter Waves》2005,26(8):1163-1173
Effects of system parameters on the side-mode suppression ratio of the fiber grating external cavity semiconductor laser are investigated by the numerical method, and the variation of the side-mode suppression ratio is discussed. It is found that an excellent anti-reflection coating provides the significant reduction of the variation due to the phase shift and the change of the internal cavity length. The laser with the low anti-reflection coating, the high coupling efficiency and the short cavity will exhibit the excellent side-mode suppression ratio. 相似文献
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Anti-reflection coatings of solar cells have been fabricated using different techniques. The techniques used include SiO2 thermal oxidation, ZnO/TiO2 sputtering deposition and porous silicon prepared by electrochemical etching. Surface morphology and structural properties of solar cells were investigated by using scanning electron microscopy and atomic forces microscopy. Optical reflectance was obtained by using optical reflectometer. I-V characterizations were studied under 80 mW/cm2 illumination conditions. Porous silicon was found to be an excellent anti-reflection coating against incident light when it is compared with another anti-reflection coating and exhibited good light-trapping of a wide wavelength spectrum which produced high efficiency solar cells. 相似文献
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The lowest threshold current of the external-cavity semiconductor laser with fiber Bragg grating using genetic algorithms
is investigated. Effects of the external cavity length, coupling efficiency and anti-reflection coating reflectivity on static
characteristics, such as L-I curves and side mode suppression ratios (SMSR) are investigated by using multi-mode rate equation.
It is found that the reflectivity of the anti-reflection coating for low-threshold performance needs to be increased at the
cost of the stability of the fiber grating external-cavity semiconductor laser. The optimal external cavity length obtained
by genetic algorithms can be used to obtain the lowest threshold current for sacrificing a little SMSR. However, with the
decrease of AR-coating reflectivity, output powers and SMSRs are slightly dependent on the external cavity length. 相似文献
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C.-H. Chan A. Fischer A. Martinez-Gil P. Taillepierre C.-C. Lee S.-L. Yang C.-H. Hou H.-T. Chien D.-P. Cai K.-C. Hsu C.-C. Chen 《Applied physics. B, Lasers and optics》2010,100(3):547-551
In this study, we demonstrate a cost-effective method to deposit an anti-reflection coating on glass. Hexagonally arranged layers are formed by a monolayer of microspheres deposited by a dip-coating method. After the deposition of the microspheres with diameter of 200 nm, the forward transmission of the glass substrate is enhanced from 88.8% to 97.2% at an incident wavelength of 600 nm, demonstrating that the nano-scale monolayer coating of microspheres can be used as an anti-reflection layer. This method can be applied to organic light emitting diodes and solar cells in order to enhance the forward transmission of the light at the interface of the optoelectronic devices. 相似文献
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