共查询到20条相似文献,搜索用时 78 毫秒
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棱镜扩束器(PBE)广泛用在准分子激光腔内光谱压窄系统中,可以有效降低光束发散角和系统内能量密度。为了实现窄线宽激光输出并降低腔内损耗,需要对棱镜扩束器的棱镜个数、单棱镜扩束倍数和棱镜顶角进行优化设计。根据棱镜扩束倍数的理论,数值分析了入射角、顶角和出射角对棱镜扩束倍数的影响,并在实验上很好地验证了扩束倍数与入射角的关系。此外,推导了激光器线宽压窄系统实现一定激光线宽输出所需的总棱镜扩束倍数。优化设计了扩束倍数M为13.3的氟化钙消色散棱镜扩束器,在此基础上,实现了0.915pm的窄线宽ArF激光输出,实验结果与理论设计吻合。 相似文献
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针对传统的二次非球面折射型激光扩束器存在不易加工、装调困难、体积大、重量大,特别是难以获得高填充比阵列透镜等不足,提出了一种利用衍射型台阶化面型近似二次非球面的激光扩束器方案,结果表明:对于典型的束腰半径为2mm的高斯光束,衍射型激光扩束器可实现2.8倍的理论扩束比。为了保持扩束过程中激光模式的稳定性,提出了不同区域给定不同台阶数的两类复合结构,解决了扩束过程中保真度和二元衍射元件加工特征尺寸无法同时满足的问题,改进后的系统保真度达95.82%,各区域最小光刻线宽均大于2μm,能够满足现有光刻加工技术要求。对影响系统保真度主要误差的分析结果表明:离轴误差在-1~1mm,目镜和物镜倾斜误差分别小于0.1mm和1.68mm时,系统保真度仍大于95%,方便装调。 相似文献
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本文对激光光束通过望远系统后光束的变化进行了分析,并对6倍望远镜进行了激光损伤和破坏的实验研究,实验结果表明,激光对望远系统的损伤破坏主要是热效应所致,损伤破坏的情况与激光的能量,波长,脉冲宽度和望远系统的结构有关。 相似文献
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A laser-beam writing system is developed for large-area optical waveguide fabrication. Single-mode embedded channel optical waveguides are successfully fabricated on both 4- and 8-in silicon substrates using deuterated fluoromethacrylate polymers by laser-beam writing in photoresist and dry etching. The propagation loss of the waveguides is as low as 0.1 dB/cm at 1.3 μm 相似文献
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Free-space optical (FSO) systems have attracted much attention from both research and application perspectives owing to their many benefits, such as license-free operation, low-cost, and high data rates. This paper investigates the ergodic capacity of FSO systems, which is an important metric of system performance. The stochastic temporary laser-beam blockage, pointing errors, and atmospheric turbulence are simultaneously considered. The results illustrate that the link blockage causes a decreased ergodic capacity. We show that to maximize the ergodic capacity, there is an optimal value of the laser-beam radius at the waist, which largely depends on pointing errors; however, it is independent of the atmospheric turbulence and the probability of link blockage. 相似文献
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《Electron Devices, IEEE Transactions on》1982,29(11):1718-1722
Q-switched green laser-beam scanning has been investigated as a new approach for lifetime doping in silicon. The effects of the laser-beam scanning have been studied by p-n junction photoresponse, MOS CV lifetime measurements, and p-n junction leakage measurements. The results indicate there is a range of average laser power (0.5-0.8 mW under certain scanning conditions) over which minority-carrier lifetime decreases at least 3 orders of magnitude. The depth within which minority-carrier lifetime changes significantly is more than 0.4 µm. Also the doping may be accomplished without disturbing passivation and with no visible damage. Furthermore, the lifetime changes are shown to be stable for subsequent thermal processing up to 400°C. 相似文献
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Seam-tracking ability of a laser-welding system is important for welding process, and the accurate detection of deviations between the laser-beam focus and the weld seam position is prerequisite for seam-tracking control. Infrared image sensing and visual recognition techniques for real-time seam tracking monitoring during high-power fiber laser welding is researched to improve the accuracy of seam-tracking ability. Molten pool images are caught by an infrared sensitive high speed camera arranged off-axis orientation of a laser-welding head which is fixed to a robot. Through the image processing, the feature detection of a near-infrared image is used in visual tracking. The gray-value gradient of near-infrared image is calculated and the keyhole margin of a molten pool is also detected. Combining the gradient and keyhole margin of a molten pool image, the thermal gradient parameter based on the thermal distribution of a molten pool is extracted. As a visual feature in robot control system, this parameter can be used to determine the deviations between the laser-beam focus and the weld-seam center. In comparison with direct detection of the narrow gap position, this parameter can be measured easily and the delay error resulted from the forerun of the sensor can be eliminated. This provides a practical approach to detect the deviations and the possibility to adjust the laser-beam focus position in real time, which can sensibly promote seam tracking accuracy. The proposed algorithm is tested during a butt-joint laser welding of Type 304 austenitic stainless steel plates at a continuous wave fiber laser power of 6 kW and 10 kW. Its effectiveness is confirmed by the welding experiments. 相似文献
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Novel high magnification zoom laser beam expander 总被引:1,自引:0,他引:1
GAO Hong-yun FU Ru-lian ZHUO Ran-ran 《光电子快报》2006,2(6):436-438
At present ,beam expanding as a common shapingmethod has been usedin many applications suchaslaserradar[1],interference measure[2],lasers[3],laser holo-gram[4],x-ray optics[5],fiber optics[6]and so on.Zoombeamexpander has been used in more applications fo… 相似文献
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光纤合束器是一种先进的将泵浦光耦合进双包层光纤的器件.介绍了这种器件的结构和优点,以及它在大功率光纤激光器和光纤放大器中的应用,并对它的研制过程进行了探讨. 相似文献
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S. Yu. Otrokhov 《Journal of Communications Technology and Electronics》2008,53(5):584-588
The effect of higher radiation modes on the characteristics of a laser frequency reference with an external interferometer is considered. It is shown that, in the case of local laser-beam detection, higher modes can have a significant effect on the shift in the reference frequency through the pulling mechanism. 相似文献