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1.
研制了一种新型的预电离结构——管状预电离器,并将其应用于可调谐TEA CO2激光器。利用光栅选线方案,采用光栅谐振腔,实现了激光的调谐输出。在输出耦合率为50%、气压为40 kPa的条件下,10P(20),10R(20),9P(20),9R(20)四条谱线获得的最高电光转换效率,分别为9.5%,9.7%,9.8%,9.8%。实现了激光器的高重复频率可调谐输出运转,测量了上述4条谱线激光输出的脉冲能量及平均功率,在输出耦合率为50%、气压为30 kPa的条件下,重复频率最高可达190 Hz, 此时的10P(20),10R(20),9P(20),9R(20)四线的平均功率分别为322,321,340,338 W。  相似文献   

2.
Five and six-temperature models for the CO2–N2–He system are used to describe the process of the dynamic emission in the TEA CO2 laser. All physical constants and relaxation rates related to these models are examined to estimate the output pulse parameters as a function of the input parameters. The two pumping processes implemented; empirical function and differential equation show a good agreement with the experimental data.  相似文献   

3.
An in situ mass-spectrometric sampling technique has been developed for lifetime studies of TEA CO2 lasers. Using the new technique, an analysis of the gas components of a TEA CO2 laser during its lifetime has been performed. The results show that the laser output pulse energy was strongly influenced by the oxygen concentration inside the device.  相似文献   

4.
设计了一种非对称电极,这种非对称电极的阳极是Chang电极或Ernst电极,阴极是由直线和圆弧构成的简单电极。通过比较和分析非对称电极和对称电极的特点发现,非对称电极系统中简单电极的边缘电场起伏最大。采用有限元方法计算了非对称电极系统中的简单电极取不同的直线长度和弧线半径时,非对称电极系统的电场分布,给出了选择非对称电极系统中的简单电极参数的依据。结果表明:这种非对称电极系统结合了解析电极和简单电极的优点,通过选择非对称电极系统的简单电极参数,它可以在TEA CO2激光器中产生边缘电场起伏小于0.06,且满足电极表面均匀场面积宽度要求的电场。  相似文献   

5.
以TEA CO2激光器通常采用的平-凹光学稳定腔为基础,提出了一种新的波长选支方法——输出窗口镀膜选支方法。利用一台高平均功率TEA CO2激光器进行了选支实验研究,结合现有光学镀膜技术,得到了中心波长为9.3 μm的激光单谱线输出,其单脉冲能量及平均功率与激光器原中心波长10.6 μm单谱线输出的相应参数基本相当。研究发现,以相同单脉冲能量激光照射热敏纸时,中心波长9.3 μm激光光斑与中心波长10.6 μm的明显不同。同时,还设计出两波长窗口密闭免调切换装置,在一台激光器上实现了10.6,9.3 μm两个中心波长激光同等功率水平的免调切换输出,切换位置误差小于5″,密封性能满足使用要求。  相似文献   

6.
Experimental and theoretical study of VI characteristics of UV pre-ionized TEA CO2 laser has been carried out for a variety of gas mixtures emitting different optical pulse shapes suitable for various applications. Coupled differential equations have been solved to model the pulse excitation circuit using the numerically calculated values of ionization coefficient (α), attachment coefficient (β) and drift velocity (Ud) as functions of E/N (i.e. electric field to neutral particle density ratio) for chosen gas mixture. Calculated and experimental V–I characteristics for gas mixtures (CO2:N2:He::1:2:3, 1:1:4, 1:1:5 and 1:0:4.7) show a good agreement. It has been shown that gas mixture has a dominant effect on the delay between pre-ionization and main discharge; thus, determining the long-term stability of discharge. The excitation pulse duration increases with increase in molecular content of gas mixture (i.e. amount of CO2 and N2 in gas mixture).  相似文献   

7.
A mathematical model, based on the Landau–Teller equations of six-temperature model for the CO2–N2–He–CO system, to describe the process of dynamic emission in tunable TEA CO2 lasers is introduced. In this model, the Landau–Teller equations are rewritten with regard to fine longitudinal mode frequencies in the laser resonator. These revised equations can be utilized to estimate the laser output spectra as well as other laser output pulse parameters. Examples are given to show the modeling results of non-tunable, grating tuned or injection-locking TEA CO2 lasers.  相似文献   

8.
高功率气体激光器的非对称复杂电极系统中,电极参数的变化以及预电离结构的引入将会使所设计的均匀电场发生具体的改变。采用高精度有限元方法,对这类复杂电极系统进行建模并且计算其电场分布,根据分析结果更合理地指导激光器设计。对一种典型的非对称复杂电极系统TEA CO2激光器,应用该方法并结合了预电离过程,研究了引入预电离器导体和变化电极形状对电极表面的电场强度起伏和放电空间的均匀电场面积产生的影响。结果表明:通过这种预先模拟,合理选择电极构型参数和预电离结构安装位置,可以产生性质较好的均匀电场以及效率较高的激光输出。  相似文献   

9.
Slate is a natural stone which has the characteristic that shows a well-developed defoliation plane, allowing to easily split it in plates parallel to that plane which are particularly used as tiles for roof building. At present, the manufacturing of slate is mostly manual, being noisy, powdery and unsafe for the worker. Thus, there is a need to introduce new processing methods in order to improve both the working conditions and the quality of the products made of slate.Following the previous work focused on the drilling and cutting of slate tiles using a Nd : YAG laser, we present in this paper the results of the work carried out to explore the possibilities to cut slate plates by using a CO2 laser. A 1.5 kW CO2 laser was used to perform different experiments in which, the influence of some processing parameters (average power, assist gas pressure) on the geometry and quality of the cut was studied. The results obtained show that the CO2 laser is a feasible tool for a successful cutting of slate.  相似文献   

10.
基于国产非晶态合金磁芯,研制了采用可控硅开关、脉冲升压变压器、以及两级磁脉冲压缩网络的全固态激励电路系统,并且应用于放电体积为29 cm3,工作气压为100 kPa的电晕预电离小型TEA CO2激光器。讨论了提高系统能量传输效率和减小系统体积的设计方法,并且测量了系统的工作性能以及各部分的能量损失。实验结果表明:磁脉冲压缩网络的能量传输效率大于83%,全固态激励系统的总效率大于75%;连接激光器负载时,输出脉冲的电压峰值约为22 kV,电流上升时间约为100 ns;得到了脉冲能量109 mJ,宽度70 ns的激光输出,激光器整体效率约为3.3%。在目前的封离体积与气体循环方式限制下,激光器最大重复频率约为100 Hz,而激励电路部分可以达到400 Hz的工作频率。  相似文献   

11.
This paper presents the results of the calculation of the parameters of the active medium of a fast-axial-flow CO2 laser using numerical methods in the framework of a one-dimensional approximation of the set of continuity equations, Bernoulli equation, equation of gas state, energy equation and multi-temperature rate equations with regard to diffusion for the gas flow in the cylindrical discharge tube. The spatial distribution of the small-signal gain and gas temperature along the gas flow direction have been calculated for a given set of initial conditions, namely, gas flow velocity, gas pressure and the tube diameter. In addition, the dependence of small-signal gain, the asymmetric stretch vibrational temperature of CO2 (T3) and the gas temperature on the discharge current were studied.  相似文献   

12.
采用振镜系统结合10.6 m的CO2激光,对熔石英表面损伤点进行辐照,成功地修复了直径500 m的大尺寸损伤点,损伤修复后表面无烧蚀残留,损伤内部完全愈合,无气泡和残余裂纹。和定点修复方式相比,这种修复具有修复尺度大、面形影响区域小、应力分布范围小的优势。80%扫描辐照修复的损伤点的初始损伤阈值恢复甚至超过了基底的初始损伤阈值。  相似文献   

13.
A helium-free mini TEA CO2 laser has been operated at a repetition rate of 100 Hz wherein the gas re-circulatory loop consisting of heat exchanger and catalytic converter, mandatory for conventional repetitive operation of such lasers, have been totally dispensed with. The laser utilized inexpensive molecular gases alone that were simply flown out transversely through the inter-electrode region by an open gas flow system. The active medium was energized by making use of a spiker-sustainer excitation scheme. At this repetition rate, the laser produced an average power of 3.50 W.  相似文献   

14.
We have developed a 1-D spatially-dependent model and simulation code to study the dynamics of TEA CO2 lasers. In this paper we will discuss the motivation for developing the model and present the simulation details. We have compared and verified the simulation results with the previous 0-D model, and with the measurements of a TEA CO2 laser. With spatial resolution, the 1-D simulation is in better agreement with experimental results compared with the existing 0-D model.  相似文献   

15.
The various techniques used for multiline operation of TEA CO2 lasers are reviewed with particular reference to the multiline laser parameters of interest in laser applications.  相似文献   

16.
研究了CO2激光对单晶硅太阳能电池的辐照效应,并对其损伤机理进行了分析。在激光功率密度较低而不能使电池产生物理损伤时,电池的性能会因在被辐照过程中温度的升高而产生暂时性降低;当激光功率密度高到使电池产生物理损伤时,电池的输出性能便产生永久下降。通过对比激光辐照前后电池伏安特性曲线和输出功率曲线的变化情况,结合对损伤形貌的分析,表明:当电池被物理损伤之后,电池的性能会出现大幅度下降,硅PN结的严重烧蚀破坏是主要原因。  相似文献   

17.
对在三镜腔中插入法布里-珀罗(F-P)标准具实现单纵模激光输出的方法进行了分析,计算了激光器的输出特性。设计研制了一台单纵模可调谐TEA CO2激光器。采用在三镜腔中插入F-P标准具的方法实现了单纵模激光的调谐输出。当激光器以5 Hz重复频率运转时,得到9P(16)谱线能量大于200 mJ,脉冲宽度约为150 ns。  相似文献   

18.
The O3 absorption coefficients for the rotational lines P(12)–P(28) of the 9.4 μm emission band of the CO2 laser are presented. Measurements were made in O3–air dilute mixtures (20–600 ppm) at 25°C and a total pressure of 1013.25 h Pa using a frequency stabilized cw CO2 laser and values have been determined with greater precision than in previously reported studies.  相似文献   

19.
A compact capacitor-transfer TEA CO2 laser of 180 mJ output energy and 50 ns pulse duration in half width was designed and constructed for field use. This laser is suitable for laser microprobe spectrochemical analysis on geological and mining samples. Experiments show that the use of helium as a surrounding gas suppresses the continuous emission spectrum of the plasma, thus increasing the S/N ratio. Using glass as standard samples, the minimum detectable concentrations are estimated with Zn neutral line and F ionic line to be 60 ppm and 500 ppm, respectively.  相似文献   

20.
Laser ablation of Upilex-S polyimide films 80 μm thick was performed in air using a pulse TEA CO2 laser with wavelength 9.3 μm. A halo surrounding the hole was observed, which is covered with sub-micro particles. Pieces of ablation products protrude from the ablated surface, leading to considerable roughness of the ablated area. Chemical and structural changes of Upilex-S polyimide film surface irradiated by the pulse TEA CO2 laser in air were analyzed by X-ray photoelectron spectroscopy (XPS). Relative C content in the ablated area was found to be higher, whilst both O and N contents were lower than in the untreated area. This means that TEA CO2 laser ablation released both the O and N atoms. Also, the peak areas corresponding with carbonyl group (C=O) in the imide system were reduced much more and a new component at 287.0 eV assigned to the amide structure (N---C=O) was detected after laser ablation. These suggest that the pyrolysis of the Upilex-S polyimide was the decomposition of the imide ring between the nitrogen/aromatic carbon atom and carbonyl carbon atom. In addition, another new component arising from >C=O groups was also detected for higher fluence (7.83 J/cm2), and its peak areas is very small. This result indicates that the slight oxidation may take place with higher fluence during laser ablation in air. Based on above-mentioned experimental results, a possible thermally-induced decomposition path of Upilex-S polyimide ablated by TEA CO2 laser is presented.  相似文献   

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