双尺度织构的激光光刻工艺

搭建了双光束激光干涉光刻系统和激光快速扫描系统。利用干涉光刻系统,实现了不同周期、不同深度、大面积的表面规则光栅织构的构筑。利用激光快速扫描器的二维扫描功能,通过控制激光功率和扫描速度,对曝光量和填充线条间距进行了优化。提出了两种双尺度复合织构的制备方法：一种是在激光快速扫描系统中对抗蚀剂表面分别进行x, y方向的扫描光刻,然后在干涉光刻系统中进行双光束干涉光刻;另一种是在激光干涉光刻系统中进行两次曝光,每次曝光的入射角不同。实验结果表明：这两种方法在制备双尺度复合织构方面具有快速、廉价、操作简易等优点。     

光刻及离子束蚀刻技术制作DNA芯片模版

采用光刻及离子束蚀刻技术制作面阵石英DNA芯片模版,利用扫描电子显微镜（SEM）和表面轮廓仪测试了所制石英DNA芯片模版的表面微结构形貌特征,分析了所制石英DNA芯片模版出现图形畸变的原因。所用工艺为在其它衬底材料表面制作更大规模及具有复杂结构的大面阵DNA芯片模版奠定了基础。     

光刻及离子束蚀刻技术制作DNA芯片模版

 采用光刻及离子束蚀刻技术制作面阵石英DNA芯片模版，利用扫描电子显微镜（SEM）和表面轮廓仪测试了所制石英DNA芯片模版的表面微结构形貌特征，分析了所制石英DNA芯片模版出现图形畸变的原因。所用工艺为在其它衬底材料表面制作更大规模及具有复杂结构的大面阵DNA芯片模版奠定了基础。     

多光束无掩模光刻系统

介绍了一种多光束无掩模光刻系统,该系统利用空间光调制器数字微反射镜(DMD)对405 nm的激光光束进行调制,控制波带片阵列及纳米透镜阵列聚焦,利用聚焦点阵配合纳米移动平台进行扫描光刻。介绍了该无掩模光刻实验系统结构及工作原理,并给出了多光束光刻的实验结果。实验表明:利用普通蓝紫光源和聚焦元件阵列可实现分辨率为400 nm的多光束并行光刻。     

非晶硅太阳能电池高速激光划线实验研究

用波长为532nm的调Q倍频激光器作为光源,对非晶硅太阳能电池板进行高速激光划线实验。通过原子力显微镜对不同激光扫描速度下划线蚀刻深度、热影响区尺寸、切口倾角以及线能量密度等进行测量,分析了划线效果对电池效率的影响。结果表明,当扫描速度为0.3m/s时,划线效果较理想。     

光刻全息图的蚀刻条件研究

本文提出发展蚀刻二元元件的工艺,其中最重要的是选择适当的蚀速比,它是制作具有连续厚度分布的浮雕型光刻全息图的关键,文中给出了反应功率一定时腐蚀气体流量和蚀刻速率的关系曲线,找到了合适的工作点,根据这些结果,制作成功性能优良的全息光学元件.     

高强度激光薄膜的研制

为提高激光薄膜的抗激光强度,实验研究了薄膜新材料、镀膜基体的表面粗糙度和洁净度,薄膜中的杂质污染,镀膜后的热处理,以及小光斑扫描激光预处理对薄膜的损耗和抗激光强度的影响。     

高强度激光薄膜的研制

为提高激光薄膜的抗激光强度,实验研究了薄膜新材料、镀膜基体的表面粗糙度和洁净度,薄膜中的杂质污染,镀膜后的热处理,以及小光斑扫描激光预处理对薄膜的损耗和抗激光强度的影响。     

基于光克尔门空间扫描单次激光信噪比测量

提出一种基于光克尔门空间扫描的单次激光信噪比测量方法.在该方法中,门光和探测光在光克尔介质中正交传输,通过光克尔门对探测光的空间扫描实现激光信噪比测量.采用该测量方法进行了单次激光信噪比测量的实验研究,测得时间窗口和分辨率分别为88.2ps、2.7ps.由于取样门是由光克尔效应来控制,因此该激光信噪比测量方法对于待测激光的波长没有限制.     

高强度激光薄膜的研制

 为提高激光薄膜的抗激光强度,实验研究了薄膜新材料、镀膜基体的表面粗糙度和洁净度,薄膜中的杂质污染,镀膜后的热处理,以及小光斑扫描激光预处理对薄膜的损耗和抗激光强度的影响。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.