高灵敏度集成光偏振干涉仪特性及生化传感应用研究

利用射频溅射技术在平面单模玻璃波导表面局部淀积一层Ta₂O₅梯度薄膜, 形成复合光波导芯片, 结合棱镜耦合法制备了一种集成光偏振干涉传感器. 基于四层平板波导模型理论分析了复合光波导表面折射率灵敏度S_RI与Ta₂O₅梯度薄膜等效厚度T_eq的关系, 结合实验测定的S_RI得出了本工作中所使用Ta₂O₅梯度薄膜的T_eq ≈ 33.021 nm, 进一步得出芯片吸附层厚度灵敏度S_ab≈ (2.412× 2π) nm^-1. 利用该复合波导偏振干涉仪结合Lorentz-Lorenz有效介质理论测得了市售食用白醋中醋酸的浓度, 并以市售牛栏山二锅头酒为例进行了白酒掺水和掺甲醇的测试, 结果表明, 白酒掺水或甲醇前后的折射率改变量与掺杂量成准线性变化关系; 原位实时监测了丁酰胆碱酯酶的动态吸附过程及细胞色素c/聚苯乙烯磺酸钠的分子自组装过程, 并利用测得的位相差变化结合芯片吸附层厚度灵敏度S_ab 获得了蛋白质表面覆盖度.     

SR-FEL宽带腔镜与双带腔镜光学膜系实验研究与研制

利用“电子束蒸发沉积薄膜生长技术+离子束溅射沉积薄膜生长技术”、“HfO₂/SiO₂+Al₂O₃/SiO₂+M-SiO₂”复合光学膜系设计技术、400°C4h高温处理技术, 研制的SR-FEL宽带腔镜光学膜系在355nm中心波长的绝对光学反射率测量值为R(355nm)=99.45%, 反射光谱带宽测量值为Δλ(R≥99.00%)=75nm; 研制的355nm/248nm双带腔镜光学膜系, 在355nm中心波长, 其绝对光学反射率测量值为R(355nm)=99.69%, 反射光谱带宽测量值为Δλ(R≥99.00%)=59nm; 在248nm中心波长, R(248nm)=98.21%, 绝对光学反射率光谱带宽测量值Δλ(R≥99.00)=9mm, Δλ(R≥98.00%)=33nm.     

缓冲层对LBO晶体上1 064 nm，532 nm增透膜附着力的影响

 采用电子束蒸发方法在LBO晶体上制备了无缓冲层和具有不同缓冲层的1 064 nm,532 nm二倍频增透膜。利用分光光度计、纳米力学综合测试系统以及调Q脉冲激光装置对样品的光学性能、附着力以及抗激光损伤性能进行了测试分析。结果表明：所有样品在1 064 nm和532 nm波长的剩余反射率都分别小于0.1％和0.2％;与无缓冲层样品相比,预镀Al₂O₃缓冲层样品的附着力提高了43.1％,具有SiO₂缓冲层样品的附着力显著提高,而MgF₂缓冲层的插入却导致薄膜附着力降低。应用全塑性压痕理论和剪切理论对薄膜的附着力增强机制进行了分析。薄膜的抗激光损伤性能分析表明,SiO₂缓冲层也有助于改进薄膜的激光损伤阈值。     

真空退火对355nm Al2O3/MgF2高反射薄膜性能的影响

 采用电子束蒸发沉积技术制备了355nm Al₂O₃/MgF₂ 高反射薄膜，并在真空中进行不同温度梯度的退火，用X射线衍射（XRD）观察了薄膜微结构的变化，用355nm Nd：YAG脉冲激光测试了薄膜的激光损伤阈值，用Lambda 900光谱仪测试了薄膜的透过和反射光谱。结果表明在工艺条件相同的条件下真空退火过程对薄膜的性能有很大的影响，退火温度梯度越小的样品，吸收越小，阈值越大，并且是非晶结构。选择合适的真空退火过程可以减少355nm Al₂O₃/MgF₂ 高反射膜的膜层吸收，提高薄膜的激光损伤阈值。     

波长1315nm的石英窗口增透膜

 用Ta₂O₅/SiO₂膜系镀制了石英窗口增透膜。并在优化膜系,改进膜厚控制后,使得1315nm波长单面剩余反射率降到0.05%。     

波长1064nm脉冲激光高阈值反射膜的研制

 研究HfO₂/SiO₂高反射膜的制备工艺及其激光诱导损伤阈值的比较测试,分别采用了反应蒸镀HfO₂、反应离子辅助蒸镀HfO₂、反应离子辅助蒸镀金属Hf的源材料形成HfO₂薄膜。采用这三种工艺制备了HfO₂/SiO₂高反射膜,在中心波长1064nm处,反射率 R≥99.5%,其中反应蒸镀HfO₂/SiO₂高反射膜损伤阈值最高,可达60J/cm²(1064nm,5ns)。     

ZrO2/ SiO2多层膜的化学法制备研究

 分别以ZrOCl₂·8H₂O 和正硅酸乙酯为原料,采用溶胶-凝胶工艺制备了性能稳定的ZrO₂和SiO₂溶胶。用旋转镀膜法分别在K9玻璃和单晶硅片上制备了ZrO₂/ SiO₂多层膜。采用溶剂替换和紫外光处理等手段,有效地解决了ZrO₂/SiO₂多层膜中膜层开裂和膜间渗透等问题。应用扫描电子显微镜观测了薄膜的表面和剖面微观形貌,并用椭偏仪测得薄膜的厚度和折射率,研究了薄膜厚度、折射率与热处理温度、紫外光处理时间的关系,对所获得薄膜的紫外-可见、红外光谱进行了分析。用输出波长1064nm ,脉宽15ns 的电光调Q光系统产生的强激光进行了单层膜的辐照实验,结果发现溶剂替换后激光损伤阈值有所提高。     

光斑尺寸对光学薄膜元件温升的影响

 实验测量了波长1 064 nm， 10 kHz高重复频率激光辐照下在白宝石、石英玻璃、K9基片上制备的Ta₂O₅/SiO₂高反膜的温度变化，有限元分析的结果与实验结果相一致。用ANSYS程序计算了不同光斑直径、相同功率激光和相同功率密度激光辐照下薄膜元件温升的变化。结果表明：相同功率激光辐照光学薄膜元件时，光斑大小只影响激光辐照点的温升，对基板温升没有影响。基板温升只与激光功率有关，激光功率越大，基板温升越大。相同功率密度激光辐照光学薄膜元件时，光斑越大，激光辐照点温度及基板温度均越高。从激光损伤的热效应考虑，小光斑激光辐照时，光学薄膜的激光损伤阈值较高。     

多孔TiO2/Al/SiO2纳米复合结构的紫外光吸收特性研究

在SiO₂玻璃衬底上用脉冲激光沉积(PLD)技术，分别沉积Ti和Ti/Al膜，经电化学阳极氧化成功制备了多孔TiO₂/SiO₂和TiO₂/Al/SiO₂纳米复合结构. 其中TiO₂薄膜上的微孔阵列高度有序，分布均匀. 实验研究了Al过渡层对多孔TiO₂薄膜光吸收特性的影响. 结果表明：无Al过渡层的多孔TiO₂薄膜其紫外吸收峰在27     

SiO2半波覆盖层对HfO2/SiO2高反膜激光损伤的影响

 研究了SiO₂半波覆盖层对HfO₂/SiO₂高反射膜1064nm激光损伤的影响,分析薄膜的激光损伤特性及图貌得出, 对于单脉冲（1-ON-1）激光损伤,SiO₂半波覆盖层能提高HfO₂/SiO₂高反膜的激光损伤阈值;可显著降低激光损伤程度,减小灾难性损伤发生的概率;可大幅度提高HfO₂/SiO₂高反膜膜的抗激光损伤能力。     

Accuracy design of ultra-low residual reflection coatings for laser optics

Refractive index inhomogeneity is one of the important characteristics of optical coating material, which is one of the key factors to produce loss to the ultra-low residual reflection coatings except using the refractive index inhomogeneity to obtain gradient-index coating. In the normal structure of antireflection coatings for center wavelength at 532 nm, the physical thicknesses of layer H and layer L are 22.18 nm and 118.86 nm, respectively. The residual reflectance caused by refractive index inhomogeneity(the degree of inhomogeneous is between -0.2 and 0.2) is about 200 ppm, and the minimum reflectivity wavelength is between 528.2 nm and 535.2 nm. A new numerical method adding the refractive index inhomogeneity to the spectra calculation was proposed to design the laser antireflection coatings, which can achieve the design of antireflection coatings with ppm residual reflection by adjusting physical thickness of the couple layers. When the degree of refractive index inhomogeneity of the layer H and layer L is-0.08 and 0.05 respectively, the residual reflectance increase from zero to 0.0769% at 532 nm. According to the above accuracy numerical method, if layer H physical thickness increases by 1.30 nm and layer L decrease by 4.50 nm, residual reflectance of thin film will achieve to 2.06 ppm. When the degree of refractive index inhomogeneity of the layer H and layer L is 0.08 and -0.05 respectively, the residual reflectance increase from zero to 0.0784% at 532 nm. The residual reflectance of designed thin film can be reduced to 0.8 ppm by decreasing the layer H of 1.55 nm while increasing the layer L of 4.94 nm.     

利用非规整膜系实现宽角度入射减偏振、减反射薄膜的研究

利用非均匀膜系理论对宽角度入射减偏振、减反射薄膜进行优化设计,分析了在宽角度入射的情况下,偏振光产生透过率不同的原因,选取了Na3AlF6、Ta2O5和Al2O3三种不同折射率材料,采用BK7作为基底,模拟设计了光谱区在500～560 nm波段、入射角为0~70°之间的多层减偏振、减反射薄膜,设计结果表明,薄膜的透过率得到大幅度提高.     

两种后处理方法对HfO2薄膜性能的影响

利用电子束蒸发和光电极值监控技术制备了氧化铪薄膜,并分别用两种后处理方法(空气中退火和氧等离子体轰击)对样品进行了处理.然后,对样品的透过率、吸收和抗激光损伤阈值进行了测试分析.实验结果表明,两种后处理方法都能不同程度地降低了氧化铪薄膜的吸收损耗、提高了抗激光损伤阈值.实验结果还表明,氧等离子体轰击的后处理效果明显优于热退火,样品的吸收平均值在氧等离子体后处理前后分别为34.8 ppm和9.0 ppm,而基频(1 064 nm)激光损伤阈值分别为10.0 J/cm2和21.4 J/cm2.     

Measurement of optical absorption in dielectric reflectors

The absorption of optical coatings can be measured by the method described with an accuracy of 0.001%. The radiation absorbed by the optical coating causes a change in the temperature of the coating and the substrate. The temperature change is measured by means of a thin-film resistance thermometer deposited on the substrate. The method was tested for laser reflectors at 1060 nm with a laser as a light source.     

太阳能玻璃表面高强度双层减反膜制备研究

用膜系设计软件设计了λ/4-λ/2的W型的双层减反射薄膜,优化了薄膜的光学常量,并使用溶胶-凝胶技术在玻璃基底上成功镀制了该双层折射率梯度的减反射薄膜.用椭圆偏振光谱仪、紫外-可见-近红外分光光度计、原子力显微镜等分析表征了薄膜的性能.结果表明,镀制了该双层薄膜的玻璃在400 nm～800 nm波段平均透过率增加了近6%,同时薄膜显示出了极佳的机械强度.     

低损耗193 nm增透膜

计算了适用于193nm增透膜设计与制备的基底与薄膜材料的光学常数,并在此基础上对193nm增透膜进行了设计、制备与性能分析.发现基底材料的吸收损耗对增透膜元件的影响很大,超过一定值时,增透膜元件的设计透过率将达不到理想水平.对单面增透膜的设计与制备结果表明,当吸收损耗降低到一定程度,散射损耗成为不可忽略的因素.采用热舟蒸发方法实现了性能良好的193 nm减反射膜,剩余反射率在0.2%以下. 关键词： 193nm 增透膜 光学损耗 剩余反射率     

可见光波段及1 064 nm波长处用于Glan-Taylor棱镜减反射膜

为了提高Glan-Taylor棱镜的透射率,研究了Glan-Taylor棱镜在可见光波段及1 064 nm波长处减反射膜膜的设计和制备.为提高薄膜和冰洲石晶体的附着力,采用沉积Al2O3为过渡层,ZrO2作缓冲层的方法,用单纯形优化的方法进行膜系优化设计.用电子束沉积和离子束辅助沉积的方法制备了多层减反射膜,并采用石英晶体振荡法监控膜厚和沉积速率.测量结果表明,在可见光波段及1 064 nm波长处的剩余反射率均小于0.5%经测试薄膜与冰洲石晶体的附着力性能良好.     

宽带减反射膜设计的一种新方法

提出实现宽带减反射膜系设计的新方法。该方法成功地设计出在可见光谱区的平均剩余反射率小于0.2％、减反射带宽390nm的四层等厚膜系;文中给出该法的理论推导、减反射限定条件及其应用的设计实例。结果表明,新的设计比传统三层减反射膜系设计具有明显的优越。     

Sol-gel preparation and characterization of nanoporous ZnO/SiO2 coatings with broadband antireflection properties

Nanoporous ZnO/SiO₂ bilayer coatings were prepared on the surface of glass substrates via sol-gel dip-coating process. The structural, morphological and optical properties of the coatings were characterized. The refractive indices of ZnO layer and SiO₂ layer are 1.34 and 1.21 at 550 nm, respectively. The transmittance and reflectance spectra of the coatings were investigated and the broadband antireflection performance of the bilayer structure was determined over the solar spectrum. The solar transmittances in the range of 300-1200 nm and 1200-2500 nm are increased by 6.5% and 6.2%, respectively. The improvement of transmittance is attributed to the destructive interference of light reflected from interfaces between the different refractive-index layers with an optimized thickness. Such antireflection coatings of ZnO/SiO₂ provide a promising route for solar energy applications.     

Broadband and high efficiency metal multi-layer dielectric grating based on non-quarter-wave coatings as a reflective mirror

This article deals with designing a broadband and high efficiency metal multi-layer dielectric grating (MMDG) used to compress and stretch an ultrashort laser pulse. The diffraction characteristics of the MMDG are analysed by using the rigorous coupled-wave method. The multi-layer dielectric used as the reflective mirror is made up of non- quarter-wave coatings. Taking the diffraction efficiency of the 1 order as the value of merit function, the parameters such as groove depth, residual thickness, duty cycle, and reflective mirror are optimized to obtain broadband and high diffraction efficiency. The optimized MMDG shows an ultra-broadband working spectrum with the average efficiency exceeding 97% over 160 nm wavelength centred at 1053 nm and TE polarization. The optimized MMDG should be useful for chirped pulse amplification.