共查询到20条相似文献,搜索用时 15 毫秒
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《Journal of Modern Optics》2013,60(10):721-724
An interferometer is described that combines the design simplicity of a laser interferometer and the insensitivity to vibration of a common-path instrument. It is used to test wave aberration in ‘single passage’. 相似文献
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Churnside JH 《Applied optics》1984,23(1):61
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Microlenses and microlens arrays were formed directly on a surface of a glass plate by use of a CO(2) laser. When the surface of a glass plate is heated locally to a working point of the glass material by use of a focused CO(2) laser beam, it tends to become a hyperboloid owing to surface tension, which results in a microlens. A profile of the microlens was measured with an ultrahigh accurate three-dimensional profilometer (Model UA3P, Matsusita Electric Industrial Company Ltd.) that utilizes a specially designed atomic force microscope. An intensity profile and a spot diameter at the focus of the microlens were measured with a microscope and a CCD system utilizing a He-Ne laser as a light source. The focused spot FWHM diameter of 1.35 mum was obtained, and the modulation transfer function was derived from the spot profile. Microlens arrays were also fabricated and characterized. 相似文献
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Liang Gongying Eric.T.T.Wong H.C.Man Xi''''an Jiaotong UniversityXi''''an The Hong Kong PolytechnicUniversity Hong Kong 《国际设备工程与管理》1997,(2)
AComparisonofLaserCladdingNi-basedCoatingonanAluminiumAloywithCO2LaserandNd:YAGLaserLiangGongyingEric.T.T.WongH.C.ManXi’anJia... 相似文献
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《Journal of Modern Optics》2013,60(8):1643-1650
The modifications introduced in the operation of a Q-modulated CO2-like laser system due to the presence of a parametric amplifier in the laser cavity are investigated. The equations of motion for the electric field and the population inversion are studied and integrated numerically. It is shown that the presence of the parametric amplifier leads to the birth of additional attractors. In general, the system follows a period doubling route to chaos and one out of the two pairs of attractors is stable. A similar behaviour is observed in the Lorenz model with a parametric amplifier or with a phase conjugate mirror. 相似文献
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Abstract This paper presents advances in development and application of the Cambridge saturation spectrometer since the Eighth National Quantum Electronics Conference in 1987. Sample cell evaluation is discussed and a molecular beam sample-cell device is presented. An application to the spectroscopy of CF3Br is described along with preliminary experiments to establish a frequency standard at 10 μm using OsO4. 相似文献
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《IEEE transactions on instrumentation and measurement》1980,29(3):168-176
It is verified experimentally that frequency differences between CO2 laser lines and the harmonics of these differences can be used as intermediate frequencies to bridge the gap between microwave frequency standards and infrared frequencies. Criteria for the design of a microwave to 30-THz frequency chain are discussed, and experimental details of the measurement of five CO2 isotope laser frequencies to an accuracy of ±2 parts in 109 are presented. The values obtained for the CO2 isotope transitions are 26334.776614 GHz for P(40) of 13C16O2, 27979.469512 GHz for R(6) of 13C18O2, 28665.704581 GHz for P(6) of 12C16O2, 29442.483293 GHz for R(30) of 12C16O2 and 33328.991337 GHz for R(8) of 12C18O2. 相似文献
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Portugal is one of the major European producers of natural stones. In the last decade, transformation of stones has been privileged in most of the companies and the quantity of finished product for exportation increased with a major added value. New technologies and processes have been investigated. For example, CO2 laser has been used for cutting, marking, and drilling. The major advantage of this tool is its flexibility, and thus, it improved the working environment significantly. This article presents a report on the use of CO2 lasers in the cutting process of marbles and limestones. The cut quality was evaluated by adjusting the laser output power and assist gas type and pressure. The CO2 laser can be used as a feasible tool for cutting ornamental stones. Due to the economic reasons, it is specially adequate for cutting nonlinear shapes where conventional cutting tools, such as the diamond wires and saws, have limitations on both the shape and the dimensions to be cut. 相似文献
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We present the design of a large-area (50 mm times 50 mm) polyvynilidene fluoride (PVDF) pyroelectric sensor array for industrial CO2 (lambda = 10.6 mum) laser beam positioning. The array dimensions were chosen to match the area typically monitored in the alignment procedure of external optics (beam steering moving arm system, for example) used to redirect the laser beam from the laser output window to a remote working station. The instrument is provided with a tilted, high reflection, ZnSe plate which partially transmits the laser beam onto the sensor array. From positioning simulations with a Gaussian laser intensity profile with a sigma = 3.2 mm standard deviation (equivalent spot size 3sigma cong 20 mm), the positional accuracy along the two orthogonal array dimensions was found to be better than 0.02 mm for an 8 times 8 array and one order of magnitude higher for a 16 times 16 array. The centroid position of a CO2 industrial laser beam was evaluated by integrating the pyroelectric current for a time comparable to the time duration (100-200 ms) of the laser pulses used in the alignment procedure. 相似文献
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Shahnazi K 《Applied optics》1998,37(12):2502-2504
The unblended ozone line at 1044.533 cm(-1) was acquired by using the frequency modulation technique. A tunable CO(2) sideband laser with a GaAs waveguide modulator with a tuning bandwidth of 20 GHz in the mid-infrared region was used for this sideband at 1-MHz frequency with a peak-to-peak amplitude of 1 V was imposed on the first tunable sideband. The signal was passed through a 1-m cell and collected with an EG&G detector. The signal-to-noise ratio obtained wasapproximately 100:1. 相似文献
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目的解决CO_2激光加工微孔膜实际生产中难以快速、精确地确定不同孔径微孔加工参数的问题,指导微孔膜包装材料的工程应用。方法在激光功率为6~30 W、打孔时间为0.4~4 ms的条件下,加工厚度为0.04,0.06,0.07 mm的PP包装薄膜和厚度为0.035,0.05,0.07 mm的PE包装薄膜,测量微孔孔径、孔长,分析处理试验数据。结果在厚度为0.035~0.07 mm的PP/PE薄膜上加工出了直径为50~400μm微孔,在厚度为0.06 mm的PP薄膜上加工出了直径为53~257μm、孔长为100~161μm的微孔。结论激光加工微孔膜,孔径随激光功率、打孔时间的增加而增大,调节激光功率和打孔时间均可获得不同孔径微孔;加工PE薄膜所需的激光能量显著大于PP薄膜;薄膜厚度越大,打孔所需的激光能量越高;微孔孔长相对于薄膜厚度有所增加,且微孔孔径越大,孔长增量越大。 相似文献
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《Journal of Modern Optics》2013,60(8):1275-1286
We studied some kinetic, fluid-dynamic and electrical problems arising in the numerical modelling of a c.w. TE high power CO2 laser operating with N2, He and CO additives. We adapted a five-temperature pulsed laser model to the c.w. case by coupling a set of fluid-dynamic equations to the kinetic set. We added the rate equation for the secondary electron density. We calculated in some detail the ionization term and fitted experimental results to determine attachment and recombination coefficients in the discharge chamber. In order to solve our equations a numerical code has been developed. By this means we investigated the effects of temperature, density and velocity variations in the flowing mixture on the small signal gain of the device. We obtained profiles in the laser chamber of the sustainer current, small signal gain and fluid-dynamic parameters. A simple (Fabry-Perot) optical cavity model has been used to calculate output power and electrical efficiency of the device. A comparison of numerical code predictions and experimental results is presented. 相似文献
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A CO2 differential-absorption lidar system has been used for the remote sensing of ammonia in the atmosphere. For CO2 lidar returns backscattered from topographic targets at ranges up to 2.7 km, the path-averaged sensitivity of the DIAL system was 5 ppb of NH3 . Concentrations of atmospheric ammonia were found to vary during the day from undetectable levels (<5 ppb) to as high as 20 ppb, depending on temperature and humidity conditions. 相似文献
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本文实验研究了几种不同菲涅耳数的孔栏限模平凹腔的输出特性,讨论了光栏孔径、腔结构参数、输出镜透过率和光轴失调等对激光功率和光束模式的影响。 相似文献