激光用高质量减反射膜的制备

激光用减反射膜要求镀膜后的基片可以在激光的输出波长处剩余反射率低于0．1％,从这一要求出发,优化设计了两种不同的膜系,并根据膜系的需求采用了两种不同的监控方法,结果发现,使用光学膜厚控制膜层厚度的精度高,误差小,可以在一定程度上提高成品率．使用光学膜厚控制手段成功地制备出用于激光系统的单点632．8nm处剩余反射率低于0.05％,表面形貌均匀且无较大起伏的优质减反射膜．     

黄光激光器聚光元件减反膜的研究

为满足589nm黄光激光器聚光元件双波段减反膜的使用要求，根据有效界面法设计原理设计膜系，以Ta2O5和SiO2为镀膜材料，使用TFC膜系设计软件对膜系进行优化，运用电子束蒸发方法和离子束辅助沉积方法，在零膨胀玻璃上镀制589nm反射率在2%~3%之间、1064nm反射率小于1%的双波段减反膜，通过膜系结构和工艺参数的优化解决了589nm反射率在2%~3%之间难以控制的问题，获得了符合聚光元件使用要求的减反射薄膜。     

1571nm超窄带干涉滤光片的研制

针对现代光通信中的核心元件之一-密集型波分复用系统中极窄带光学薄膜干涉滤光片的指标要求,在WMS02基片上研制中心波长为1571nm,-0.5dB(透过率为89.12%)带宽大于0.25nm,-25dB(透过率为0.32%)带宽小于1nm的超窄带干涉滤光片.根据薄膜设计理论采用四分之一波长的规整膜系进行膜系设计.应用离子辅助真空镀膜技术,选用Nb2O5/Ta2O5和SiO2氧化物硬质薄膜材料进行实验,重点解决了膜厚均匀性的问题,制备出符合使用要求的滤光片.     

指纹仪系统宽截止短波通滤光片的研制

为满足指纹仪系统中光学元件的使用要求,常采用干涉截止滤光片使一部分光透过而另一部分光截止,由于截止带要求较宽,为了展宽截止带,采用在一个多层膜的基础上加镀一个不同中心波长多层膜的方法设计膜系,通过对膜系的优化压缩了通带的波纹,用电子束蒸发法进行膜层制备,采用石英晶体振荡法控制膜厚,通过对工艺参数的调整有效的减少了TiO2材料的吸收,最终制备出的膜层在380～550nm平均透过率T>90%,570～900nm平均反射率R>99%,满足指纹仪系统的使用要求。     

抗激光损伤薄膜的研究

针对工作波长为532nm和1064nm的Nd:YAG倍频激光器,以防护人眼为目的,设计并优化倍频膜系,选用Ta2O5和S iO2作为镀膜材料,采用等离子体辅助蒸发系统制备波长532nm和1064nm处同时高反射的抗激光损伤薄膜。从设计和制备两方面研究提高抗激光损伤阈值的方法,并给出最终设计曲线及实测曲线。     

808nm激光对可见光面阵CCD的干扰损伤研究

介绍了CCD光电探测器工作的基本原理及激光对CCD的干扰损伤机理.用波长为808nm的连续激光辐照CCD器件,实验中由图像采集卡采集得到相机的视频输出,同时用示波器检测CCD输出信号和垂直输出时钟信号,首次得到了808nm激光致使该种器件产生的热熔融阈值、光学击穿阈值、直接破坏阈值和致使整个器件失效的激光能量网值等有关结果.     

808nm激光诱导电化学刻蚀研究

为探讨半导体激光电化学刻蚀的工艺特性,采用808nm半导体激光作为光源,聚焦激光照射浸于溶液中的阳极上,实现激光诱导电化学刻蚀材料。在实验的基础上,通过对金属和半导体材料刻蚀的比较,分析了激光电化学刻蚀硅的工艺特点。实验表明,808nm激光诱导电化学刻蚀工艺是一个光热刻蚀过程,但不适合刻蚀半导体材料。     

基于波长复用技术的激光二极管光纤耦合方法

采用波长复用技术的激光二极管（LD）光纤耦合方法,将两个不同波长的高功率LD通过准直、波长复合、聚焦经光纤耦合以实现大功率高效率输出。用直径200μm的裸石英光纤对LD输出光束进行准直,根据波长复用的基本原理,设计了波长耦合器件,根据LD和光纤的相关参数设计了聚焦透镜组,将两只波长分别为808nm和980nm、发光面积为100μm×1μm、单管的连续输出功率2W的高功率LD通过上述方法耦合进数值孔径0.22、芯径100μm的多模光纤中,在工作电流为2.5A时,808nmLD和980nmLD总的连续输出功率为4.05W,光纤激光连续输出功率为3.33W,总耦合效率大于82%。     

多层介质滤光片的制备及激光损伤特性

为了获得具有较高激光损伤阈值的短波通截止滤光片,使用TFCalc膜系软件设计了多层膜的光谱曲线和电场强度曲线,采用电子束热蒸发技术在K9基底上制备了LaTiO_3/SiO_2组合膜堆的滤光片,通过激光辐照预处理工艺尝试提高多层膜的激光损伤阈值(LIDT),测试并讨论了激光预处理对滤光片LIDT的影响.研究结果表明:通过分析滤光片的电场强度,得到优化后的膜系是G|(HL)10 H0.5L|A,制备后滤光片的LIDT为11.7J·cm~(-2)(1 064nm,10ns);当辐照激光能量为滤光片LIDT的80%时,辐照后滤光片的LIDT为14.3J·cm~(-2)(1 064nm,10ns),较原值提高22.2%;当辐照能量为80%,采用不同辐照次数实验时,发现辐照3次后滤光片的LIDT为16.1J·cm~(-2)(1 064nm,10ns),较原值提高了37.6%.激光预处理后滤光片的表面粗糙度都有下降的趋势.     

红光Nd:YAG激光器用光学薄膜的研制

从产生660nm红光Nd:YAG激光器制作机理出发,分析了其使用的几种光学薄膜,采用光学薄膜理论的矢量合成方法.利用计算机膜系设计软件优化.并经过适当修正后得到便于控制的短波通膜系、二倍频高反射膜系,选择适当的薄膜材料和工艺参数,制备出与理论计算结果相吻合的几种光学薄膜,满足技术指标要求.     

窄带滤光片光学极值法直接监控的光学设计

窄带滤光片是应用于光谱学、激光、天文物理学、通信等各个领域的光学组件,精确控制每一层膜厚是制备滤光片的困难所在.采用光学极值法直接监控工件,可以同时制备多件滤光片.设计了监控光路和信号获得电路,通过探测到的测试信号,监控薄膜膜厚,实现了直接监控.     

基于反射光谱的单层抗反射膜的非在位膜厚精确控制

提出一种基于反射光谱分析的非在位膜厚控制技术,首先利用椭圆偏振光谱仪确定波长300～1 700 nm范围内的薄膜折射率,由此确定对应于特定波长(如1 550 nm)的最佳抗反射(AR)镀膜沉积条件。然后计算最佳AR镀膜厚度所对应的反射谱,得到相应的CIE标准色谱坐标。通过对比实测镀膜颜色和计算得到的最佳颜色,可以实现小尺寸器件端面上AR镀膜厚度的优化控制。利用这一方法,由等离子体增强化学气相沉积(PECVD)制备的SiNx单层AR镀膜,获得了4.4×10-4的反射率。     

Preparation and magnetic properties of Co-P thin films

Magnetic Co-P thin films were prepared by electroless deposition. The experiment results show that the film thickness has a significant influence on the coercivity. While the film thickness varied from 300 nm to 5 μm,the coercivity dropped sharply from 45.36 to 22.28 kA/m. As the film thickness increased further,the coercivity varied slowly. When the thickness of the film was 300 nm,the deposited film could realize the coercivity as high as 45.36 kA/m,and the remanent magnetization as high as 800 kA/m .The ...     

干涉型激发滤光片的研究

介绍用等效折射率概念设计激发滤光片的原理和计算方法,在规整膜系设计中,采用了一种自动优化非规整匹配层的方法.依照改进的设计进行多次制备,找到了最佳制备工艺和方法,最终制备出能够满足要求的滤光片组.最后,对制备的滤光片薄膜进行了各种环境实验.实验结果表明,膜层的各项指标符合设计要求.     

活性炭负载TiO2光催化降解甲醛

研究了活性炭负载TiO2所制得的光催化剂(TiO2/AC)对空气中甲醛光催化降解效果,考察了光照时间、TiO2负载量、空气流量对甲醛光催化降解效率的影响,讨论了TiO2/AC对甲醛的吸附性能以及吸附一定量甲醛后对其光催化效果的影响.结果表明:在活性炭表面负载TiO2后,对甲醛仍具有很强的吸附能力;光催化剂在空气中对甲醛的光催化降解效率可达94.06%;吸附甲醛后,稳定状态下甲醛光催化降解效率和新制备催化剂基本相同;在保证每次镀膜(TiO2)厚度达到300 nm的条件下,一次镀膜光催化效率高于多次镀膜;随着空气流量的增加,甲醛光催化降解效率有所提高.     

Combined centralized and decentralized controlfor high precision spacecraft

The improved structural filter combined with Positive Position Feedback(PPF) controller is investigated for high-precision attitude control of flexible spacecraft which consists of rigid central body a...     

Improved visible transparency of SIO<Subscript>2</Subscript>/ZNO:AL /CEO<Subscript>2</Subscript>-TIO<Subscript>2</Subscript>/SIO<Subscript>2</Subscript> multilayer films with high UV absorption and infrared reflection rate

New visible transparent, UV absorption, and high infrared reflection properties have been realized by depositing multilayer SiO₂/ZnO: Al/CeO₂-TiO₂/SiO₂ films onto glass substrates at low temperature by radio frequency magnetron sputtering. Optimum thickness of SiO₂, ZnO: Al (ZAO) and CeO₂-TiO₂ (CTO) films were designed with the aid of thin film design software. The degree of antireflection can be controlled by adjusting the thickness and refractive index. The outer SiO₂ film can diminish the interference coloring and increase the transparency; the inner SiO₂ film improves the adhesion of the coating on the glass substrate and prevents Ca²⁺, Na⁺ in the glass substrate from entering the ZAO film. The average transmittance in the visible light range increases by nearly 18%-20%, as compared to double layer ZAO/CTO films. And the films display high infrared reflection rate of above 75% in the wavelength range of 10-25 μm and good UV absorption (> 98%) properties. These systems are easy to produce on a large scale at low cost and exhibit high mechanical and chemical durability. The triple functional films with high UV absorption, antireflective and high infrared reflection rate will adapt to application in flat panel display and architectural coating glass, automotive glass, with diminishing light pollution as well as decreasing eye fatigue and increasing comfort.     

Investigation of one-dimensional Si/SiO<Subscript>2</Subscript> hotonic crystals for thermophotovoltaic filter

The spectral control is widely incorporated with the thermophotovoltaic (TPV) technology to improve the optical-electric conversion efficiency of the whole system. In order to match with GaSb photovoltaic cell, an 8-layer one-dimensional photonic crystals (PC) filter structure was designed as quarter-wave periodic structure by selecting silicon (Si) and silicon dioxide (SiO₂) as candidate materials. The multilayer Si/SiO₂ structure was developed for the matching filter to simultaneously realize the optimal matching with the spectral distribution of the high temperature emitter and the quantum efficiency of GaSb cell. The physical vapor deposition (PVD) method was used to fabricate the optical filter and the normal incidence optical property of the filter was measured within the spectral range from 0.7 to 3.3 μm. These experimental data were used to predict the spectral control performance in a TPV system. Finally, temperature performance experiments were carried out to establish its withstanding performance in high temperature environment. Supported by the National Natural Science Foundation of China (Grant No. 50776047) and Natural Science Foundation of Jiangsu Province (Grant No. BK2007726)