凹球面网栅激光直写实时控制方法

提出一种基于DuaI-Ported RAM(DPRAM)的凹球面网栅激光直写实时控制方法.采用计算机与PMAC双CPU主从并行、双向通讯和即存即取的控制方法,开发了多层嵌套并行工作程序,使计算机与PMAC实时处理、交换、显示大量控制参数和状态信息,实现了实时控制激光直写凹球面网栅.在口径200 mm、半径150 mm的涂覆感光胶玻璃凹球面基底上,激光直写出了100 μm周期网栅.微米级读数显微镜测量结果表明,网栅均匀,周期误差小于±3%,达到设计要求.     

激光直接写入系统线宽分析

在激光直接写入系统中,由于抗蚀剂内的曝光量分布和光强分布之间有差别,所以在分析线条的形状时,如果用光强分布代替曝光量分布会产生误差.本文给出了用激光直接写入技术制作二元光学元件时,抗蚀剂内曝光量的计算公式.分析了抗蚀剂内曝光区域各点的曝光量分布,它们在显影后所对应的侧壁角和线条宽度以及写入激光束运动速度变化对线条侧壁角和宽度的影响.实验结果和理论分析相吻合.     

校正激光直写邻近效应的快速方法

针对激光直写中的邻近效应的特点，提出通过直写曝光数据补偿进行光学邻近效应校正的快速，有效方法，并获得了满意的实验结果。     

全数字化激光直写转台系统

为提高极坐标激光直写设备的性能,设计成全数字化的转台系统,增强了与平台、调焦、 光强系统的同步。提出数字锁相积分、可编程PID控制及变周期稳速判据等概念,并应用于转台控制器设计。配合改进的快速光强调制系统,使极坐标激光直写设备具备制作精确环、任意弧和变宽线条的能力。     

激光直写光刻工艺技术研究

研究了利用激光直写技术制作微细图形的工艺方法，应用ＩＳＩ－２８０２型激光直写系统，通过实验，分析了激光曝光机理以及提高实用分辨力的途径。得到了激光直写系统参数与处理工艺参数之间的匹配关系，实验数据对研究制作各种掩模版、衍射光学元件以及ＡＳＩＣ电路都有应用价值。     

ISI-2802激光直写系统及其应用

介绍中国科学院光电技术研究所微细加工光学技术国家重点实验室引进的国内首台激光直写系统的工作模式、基本结构、主要性能和应用范围等，并给出用这台设备已经作出的一些掩模图形的样品。     

微粒的激光引导直写技术

基于激光引导直写的堆积成形技术可以操纵微米尺寸的材料微粒进行组装构成微结构。本文介绍了激光引导直写技术的相关原理和研究进展,同时结合实验结果对此操作过程做了探讨,最后对相关应用前景进行了展望。     

激光直写系统图形编辑软件

简要描述了一套针对激光直写系统，适用于衍射光学元件和精密码盘及其它图形的图形辅助编辑软件——ＭＡＳＫ软件，简单介绍了其功能和结构。     

消除激光直写系统中声光调制器迟滞现象的方法

激光直写是一种适用于衍射光学器件及掩模加工的方法。利用声光调制器对曝光功率进行精确控制对所制作器件的性能是至关重要的。首先描述了声光调制器的迟滞现象及其对曝光后掩模面图开的不良影响。基于这一分析,提出了一种方法来克服声光调制器迟滞现象所带来的问题。简述了此项技术的设计原理和实现。实际制作的掩模样品图案显示了所述方法的有效性。     

极坐标激光直写径向漂移理论研究

为了进一步提高光学元件的线条制作精度,建立了极坐标激光直写时线条中心径向漂移的补偿模型.首先推导了极坐标激光直写的曝光量分布模型,分析了径向漂移产生的原因,然后针对数值孔径为0.5 的光刻物镜建立了线条展宽模型和径向漂移模型,并分析了线条展宽和径向漂移的耦合关系,在此基础上分别建立了线条展宽补偿模型和径向漂移补偿模型.仿真结果表明,补偿前的径向漂移量是线条展宽量的3 倍,对径向漂移进行补偿可以很好地减小系统原理误差,提高极坐标激光直写的制作精度.     

Patterned structures fabricated on chalcogenide phase-change thin films by laser direct writing

In laser direct writing technology, the pattern is usually written in a photoresist. In this work, we use the chalcogenide phase change thin films as the laser direct writing materials, and patterned structures with different shapes and sizes were directly written with different laser wavelengths. Compared with traditional photoresist materials, the patterned structures can be directly formed in the chalcogenide phase change thin films without developing and etching procedures, and also can be directly written with different laser wavelengths. By tuning the laser parameters precisely, patterned structures with different sizes and shapes could be obtained as well. The analysis indicates that the formation mechanism of the patterned structure is mainly due to the volume expansion caused by material vaporization and the interior of the patterned structure is hollow with some solid leavings, and the chalcogenide phase change thin films are very good candidate materials for patterned structure formation.     

Fabrication of conductive silver micropatterns on an organic-inorganic hybrid film by laser direct writing

This paper describes fabrication of silver (Ag) micropatterns on a double-decker-shaped polysilsesquioxane (DDPSQ) hybrid film by laser-induced pyrolysis (LIP) of a film prepared from liquid-dispersed Ag nanoparticles. The line width of Ag micropatterns fabricated by LIP can be controlled flexibly by changing the numerical aperture (NA) value of an objective lens and the focusing point. By changing NA value of an objective lens, line widths of Ag micropatterns can be varied flexibly from 75 μm to 5 μm. The Ag micropatterns show an excellent adherence to DDPSQ surface as evaluated by adhesive tape test. The resistivity of the Ag micropattern is determined to be 4.3 × 10^− 6 Ω cm, which is comparable to that of bulk Ag (1.6 × 10^− 6 Ω cm).     

Impact of microstructures by femtosecond laser direct writing on the LED efficiency

We report on fabricating microstructures on the surfaces of LED chips by femtosecond laser direct writing. The changed trend of LED light extraction efficiency with the variation of the laser power and pulse was studied. It is found that there is an optimal surface treating condition (laser power and pulse number) in fabricating the microstructures on the surface of the LEDs to make the LED luminous flux maximum. In our experiment, the luminous efficiency of LED is close to the optimum enhancement value when the LED was surface structured with a laser power of 0.48 μW, three laser pulses at one point and the point spacing of 5 μm. In this condition, it can be improved by 23.53%.     

Effect of surface modification on laser direct joining of cyclic olefin polymer and stainless steel

Surface modification pretreatment on the laser-bonded joint between a cyclic olefin polymer (COP) and stainless steel (SUS304) was studied to determine its effect on improving the laser-bonded joint strength. The joint strength between the surface-modified COP and SUS304 was significantly improved compared with that of an equivalent un-treated joint. This improvement is caused by the generation of oxygen functional groups on the COP surface resulting in the improved adhesion of these groups with the oxide film formed on the SUS304 surface.As for the surface pretreatment of COP, the generation of bubbles in ultraviolet (UV)–ozone processing due to thermal degradation of the COP was more noticeable than with plasma pretreatment. Excessive surface modification of the COP, causing a decrease in joint strength was found to correlate with the surface energies of COP and SUS304.     

Effect of laser surface hardening on the hydrogen embrittlement of AISI 420: Martensitic stainless steel

The susceptibility of stress corrosion cracking (SCC) of AISI 420 which was surface transformed hardened by a pulsed Nd:YAG laser, was investigated in 5% sodium chloride + 0.5% acetic acid solution by the U-Bend method, in the range of pH value from 3.5 to 6, in the absence and presence of 1 ppm thiosulphate ion, at 25 and 60 °C. The results showed that the laser-treated areas are more susceptible to SCC than the base metal. Hydrogen embrittlement (HE) is the main cause of crack propagating, mostly effective on the grain boundaries and the interface between carbide particles and second phases; tempered martensite or ferrite.     

The effects of fabrication atmosphere condition on the microstructural and mechanical properties of laser direct manufactured stainless steel 17-4 PH

The effects of atmosphere conditions on microstructural and mechanical properties of stainless steel 17-4PH components fabricated by laser direct manufacturing (LDM) were investigated through measurements on phase constitution, porosity, tensile strength, fracture morphology, hardness and evolution of substrate temperature. Results showed that the samples produced in air atmosphere condition possessed higher tensile strength and hardness for both as-deposited and heat-treated states than that in Ar chamber condition, due to dispersion strengthening effect of amorphous oxide particles and nitrogen solution strengthening as a result of higher content of oxygen and nitrogen. The temperature of substrate heat accumulation was higher in Ar chamber condition, leading to dramatically lower porosity and more reverse austenite, which also contributed to the lower strength and hardness.     

CFRP-PCPs复合筋嵌入加固钢筋混凝土梁裂缝试验及计算方法研究

通过5根嵌入不同张拉控制应力的碳纤维增强塑料预应力混凝土棱柱体(CFRP-PCPs)复合筋加固钢筋混凝土梁受弯试验,对比分析试验梁的裂缝分布与发展,得到最大裂缝宽度与平均裂缝宽度在静力荷载作用下的变化特性。结果表明: 嵌入CFRP-PCPs复合筋能有效的减少被加固钢筋混凝土梁的裂缝宽度和高度。在试验基础上,根据国家现行混凝土规范,对平均裂缝间距和最大裂缝宽度计算公式进行参数修正,建立了CFRP-PCPs复合筋嵌入加固钢筋混凝土梁最大裂缝宽度计算公式,计算值与试验值吻合较好。