光学玻璃研抛用磁流变液的研究

利用智能材料之一的磁流变液 (MRfluids)作为加工工具对光学玻璃进行了精密抛光加工。讨论了适用于光学玻璃抛光的磁流变液的配制机理及磁流变液对光学玻璃抛光效果的影响因素。针对光学玻璃磁流变的抛光原理和特点 ,开发配制了适合于光学玻璃加工用的磁流变液 ,并用该磁流变液对光学玻璃进行了实验加工。结果表明 ,最终得到的光学玻璃表面经过AFM测试 ,得到Ra =1 0 1 5nm。     

探测用宽截止红外双通道帯通滤光片的设计及误差分析

为满足探测1,2丙二醇二硝酸脂有毒气体浓度的红外探测元件抑制带截止深度深、通带内平均透射比高、波纹系数小等要求,采用等效折射率理论与局部优化相结合的设计方法,选用PbTe/ZnSe作为高低折射材料,采用长波通膜系、短波通膜系以及双半波膜系设计了截止深度深、双通道、通带宽度合适的红外滤光片,通带分别为5.9～6.2μm及11.9～12.2μm,通带内平均透射比分别在90%及65%以上;对所设计的膜系进行了薄膜物理厚度和膜层折射率的误差分析。分析表明,薄膜制备时沉积速率精度应控制在3.5%以内,材料折射率的变化应控制在3%以内,与膜层折射率相比,薄膜物理厚度对平均透射比的影响小,并且双半波膜系对厚度以及折射率变化更敏感。     

提高V棱镜折射仪测试精度的V槽研究

用V棱镜折射仪测量光学玻璃的折射率,常规测试精度可以达到±5×10-5。通过分析V棱镜折射仪折射率误差的原因发现,V槽与被测件折射率越接近,测量误差越小,因而对V槽进行了改进。在最新的光学玻璃nd-vd图上选取6种高品质材料,将原来的V槽进行细分,组成新的测试标准块。对生产产品进行了实测,与标准样块进行了比对。实测结果表明,采用改进的V槽可以得到更精确的测量结果,测试精度可以达到±2×10-5。     

干涉法测量光学材料非线性折射率的方法研究

提出了一种基于楔形平板等厚干涉原理测量光学玻璃非线性折射率变化的方法。在理论分析的基础上,建立了变形的等厚干涉条纹变化△e／e与待测玻璃平片（K9玻璃）折射率变化量△nb之间的数学模型;在选取一定的实验条件下,获得等厚干涉实验测量干涉图样,并利用MATLAB对实验所得的干涉图进行图像数据处理分析计算,恢复出非线性变化光学玻璃材料的折射率变化量△nb该方法的测量精度可达10^-6。     

用激光测量液体折射率的简单方法

用激光测量液体的折射率已有许多报道，但测量方法比较繁琐，且精确度不够高.本文介绍一种用激光测量液体折射率的简单方法，此方法利用光线传播的几何关系，对液体折射率作定量测试.该方法具有设备简单、费用低廉、测量精度高等优点.1实验原理及方法利用临界角的概率束来测量液体的折射率，如图1所示.当激光束沿一条半径进入液体，即使入射光束对准容器的中心G点射入液体时，不发生折射，而在G点射出的光束发生了折射，折射角大于入射角.当人射角i增大，直到使折射角达到90°时，折射光束沿容器的直边传播.继续转动容器增大人射角，激光束…     

负折射率介质测试装置设计与测试

为深人了解负折射率媒质的奇异传输特性,基于斯涅耳折射原理,设计并加工了一种用于测试X波段((8.2-12.4GHz),以亚铁磁材料为基体,内嵌金属线阵列宏结构的负折射率介质样品折射特性的实验装置.分别测试了楔形石蜡样品和楔形负折射率介质样品在波段的折射特性,对石蜡样品测试结果的分析证明了该折射特性测试装置的有效性,对负...     

薄壁球壳受刚性球面压缩的可视化连续变形测量研究

利用三维数字图像相关(DIC)技术对薄壁球壳受刚性球面压缩的连续变形及失稳过程进行实验研究。实验中,由于乒乓球具有理想的弹塑性材料特性以及薄且均匀的壁厚,所以采用乒乓球作为压缩对象,以透明石英玻璃球作为刚性球面,通过配制与玻璃球折射率一致的折射液来消除因玻璃球折射导致的图像畸变影响,从而解决被测表面因遮挡而不可见的问题。利用三维DIC技术对与刚性球面接触的乒乓球表面在压缩过程中的连续变形进行直接测量。实验验证了所提方法的有效性。实验结果表明,通过三维DIC测量得到的乒乓球表面受刚性球面压缩产生的塑性环半径与理论结果非常吻合。     

三元结构90°转向起偏棱镜的设计研究

为了节省稀有昂贵的冰洲石晶体材料,采用冰洲石晶体与光学玻璃组合的方法,设计了一种新型起偏棱镜。设计样品为ZBaF3玻璃中间加冰洲石晶体薄片的三元结构,并通过大折射率液态胶合剂溴代萘胶合而成。该棱镜既可以实现o光的偏振输出,又可实现入射光的90°转向。实验测试结果表明:设计棱镜的透射比在80%以上,消光比优于1-0 3。理论分析和性能测试均表明:三元结构冰洲石-玻璃90°转向起偏棱镜在一般情况下,可以取代相应的纯冰洲石晶体材料的偏光棱镜。     

光学玻璃折射率精密测量中环境条件修正公式的研究

 该文指出了在光学玻璃折射率测量中目前使用的气压修正公式在折射率精密测量中的不适应与缺陷。并从空气折射率的最新计算公式入手,着重研究和提出了新的环境条件修正公式。指出在不同测试精度和不同测试条件下应采用不同的修正公式。     

费米折射率波导的包层吸收模谱特性和溶液浓度传感研究

采用0.004AgNO3-0.996NaNO3混合熔融盐,用离子交换技术在德国B270光学玻璃上制备了费米折射率分布渐变波导,理论分析了费米折射率分布渐变波导的包层吸收模谱特性.导波损耗测试实验验证了解析结果.在此基础上,提出了一种用于液体包层吸收损耗测试的双样品盒串连的波导回路.测试结果证实表征溶液包层吸收特征的折射率虚部与溶液浓度之间具有十分显著的线性关系,测试灵敏度与波导的模式和波导参量有关,尤其与波导层厚度有非常敏感的关联性.利用这个关系传感测试了13种不同浓度的耐晒果绿染料水溶液样品的浓度,结果显示测试值与实际配制浓度值的均方差小于0.07%.     

Design and numerical analysis for low birefringence silica on silicon waveguides

A new fabrication technology for three-dimensionally buried silica on silicon optical waveguide based on deep etching and thermal oxidation is presented.Using this method,a silicon layer is left at the side of waveguide.The stress distribution and effective refractive index are calculated by using finite element method and finite different beam propagation method,respectively.The results indicate that the stress of silica on silicon optical waveguide fabricated by this method can be matched in parallel and vertical directions and stress birefringence can be effectively reduced due to the side-silicon layer.     

Investigation on optical properties of Bi<Subscript>2.85</Subscript>La<Subscript>0.15</Subscript>TiNbO<Subscript>9</Subscript> thin films by prism coupling technique

Layered-perovskite ferroelectric Bi_2.85La_0.15TiNbO₉ (LBTN) optical waveguiding thin films were grown on fused silica substrates by pulsed laser deposition (PLD). X-ray diffraction (XRD) revealed that the film is highly (00l) textured. We observed sharp and distinct transverse electric (TE) and transverse magnetic (TM) multimodes and measured the refractive indices of LBTN thin films at 632.8 nm. The ordinary and extraordinary refractive indices were calculated to be n _TE=2.358 and n _TM=2.464, respectively. The film homogeneity and the film-substrate interface were analyzed using an improved version of the inverse Wentzel–Kramer–Brillouin (iWKB) method. The refractive index of the film remains constant at n ₀ within the waveguiding layer. The average transmittance of the film is 70% in the wavelength range of 400–1400 nm and the optical waveguiding properties were evaluated by the optical prism coupling method. Our results showed that the LBTN films are very good electro-optical active material.     

光学材料光学均匀性检测方法分析

光学均匀性是光学材料的重要指标，直接影响到透射光学系统的波面质量，改变系统的波相差。惯性约束聚变（Inertial Confine Fusion，ICF）激光驱动器的研制要求对材料的光学均匀性进行高精度的检测，同时兼顾洁净度要求。实验中利用斐索干涉仪实现了大口径光学材料光学均匀性的检测，并与国外检测数据进行了对比，对检测过程中的影响因素主要包括样品的厚度测量偏差及折射系数偏差进行了分析。结果表明，样品的厚度测量偏差及折射系数偏差对结果的影响较小，可以忽略。同时用两种干涉仪专用软件对大量样品测量数据进行处理，对比了不同干涉仪光学均匀性的计算结果，表明这两种情况下对光学均匀性的处理结果相符，解决了大口径光学坯件光学均匀性的检测问题。     

Birefringent modifications induced by femtosecond filaments in optical glass

We present a study of the refractive index modifications spontaneously induced by infrared femtosecond filaments propagating in the bulk of transparent solids. It was found that extended modified refractive index channels up to several mm in length can be formed under loose focusing conditions in fused silica. The observed birefringence zone at the beginning of these channels is attributed to the anisotropic stress induced via nonlinear losses in the high intensity region of the filament.     

Ultraviolet true zero-order wave plate made of birefringent porous silica

Porous Si made from (110) Si wafers exhibits strong in-plane optical anisotropy (birefringence) in the visible and near-IR ranges. Oxidation of the birefringent porous Si results in the formation of birefringent porous silica. We demonstrate that the degree of the birefringence of porous silica can be controlled by the oxidation condition, and very small birefringence can be achieved. The smallest anisotropy of the refractive index (Δn) is 0.001, which is about ten times smaller than that of quartz. The small birefringence allows us to produce true zero-order wave plates operating in the UV range.     

Effect of varying pore size of AAO films on refractive index and birefringence measured by prism coupling technique

Anodic aluminum oxide (AAO) films with different pore sizes were prepared to modulate the effective refractive index and birefringence. To investigate the relationship between the refractive index and the pore size of the AAO film, optical constants were obtained using a prism coupler with various lasers. With experimental results, the dispersion curve of alumina itself without pores was extracted using a theoretical anisotropic model. We demonstrated that AAO films could offer a wide range of refractive index and birefringence values for optical device applications. Furthermore, index profiles as a function of the thickness of the AAO films were obtained by inverse Wentzel-Kramer-Brillouin approximation to examine the optical homogeneity.     

Optical fiber refractive index sensor with temperature calibration ability

 提出一种具有温度自校准功能的光纤折射率（RI）传感器,传感头结构由2段很短的多模光纤（MMF）之间夹熔一段对折射率不敏感的光纤布拉格光栅（FBG）构成,传感头总长度为14 mm,FBG可以为折射率测量提供良好的温度校准功能。实验结果证明,该传感器的折射率灵敏度为126 nm。其干涉光谱共振波长的温度灵敏度为35.09  pm/℃,用于温度校准的FBG的温度灵敏度为11.14 pm/℃。相比于普通的折射率传感器,这种具有温度自校准功能的折射率传感器具有良好的实用前景。     

Fused silica as a composite nanostructured material

A method for calculating the refractive index of optical fused silica by applying the model of effective permittivity of composite homogeneous media is proposed and realized. The calculation was performed using the tabular data of the refractive index of crystalline α quartz and the ratio of the quartz glass and α quartz densities. It was suggested that fused silica contains nanosized pores with a glass filling number q immersed in a matrix with a density differing from the α quartz density by a factor of κ, where κ is slightly less than unity. It was established that the Maxwell-Garnett model makes it possible to calculate the refractive index of quartz glass and its dispersion in the transparency range (404 nm ≤ λ ≤ 671 nm) with a deviation less than 0.0002 from the tabular values. The calculated and experimental values coincide at q = 0.155 and κ = 0.986.     

Measurement of refractive index homogeneity of parallel optical component

In this paper, we present a method for enhancing the measurement capability of refractive index homogeneity for parallel optical components, which phase-shifting interferometry cannot handle with. With the help of wavelength-modulation phase-shifting interferometry, a series of multiple-surface interference fringes are obtained and analyzed by Fourier transform. Based on the fact that the interference fringe corresponding to each interference cavity has its own variation frequency, the wavefront aberrations induced by each interference cavity are obtained and the refractive index homogeneity is then obtained. It is proved by experiment that the enhanced method can measure the refractive index homogeneity of parallel optical components more accurately and conveniently compared with the traditional measurement approach. Therefore, it will have potential application forwards in optical measurement field.     

基于白光扫描干涉法的光纤折射率分布的测量

提出了一种光纤折射率分布的测量方法,采用白光扫描干涉技术,并在参考镜上构造与光纤样品相同的结构来克服白光相干长度短的限制,优化了光路,提高了干涉条纹间的对比度。采用与白光干涉信号的包络线呈高斯分布的Morlet小波作为小波变换的母小波进行拟合处理,得到光纤与已知折射率的匹配液之间的相对高度。通过计算获得光纤的折射率分布,并对获得的数据采用光纤折射率分布的经典函数进行拟合,得到多模光纤和单模光纤的决定系数分别为0.997 2和0.996 4。最后将实验获得的结果与官方参数进行比较,误差为0.01%,表明该种方法测量的精度较高,完全可以用来测量光纤的折射率。