并联式横向激励大气压氮分子激光器

本文介绍一种并联式横向激励大气压氮激光器。其结构非常简单，仅采用了一个简单的Blumlein放电电路，在其上并联了不同量值的陶瓷电容器，以增加传输线和储能电容器的容量。实验结果表明激光输出能量随并联电容量增加而线性增加。     

并联式横向激励大气压氮分子激光器

横向激励大气压氮分子激光器是继低压氮分子激光器发展起来的一种激光器件,它具有如下特点:①结构比低压氮分子激光器简单(激光介质在大气压下工作无需真空装置和反射与出射镜片);②在很小的激光腔体中能获得较强的激光能量;③激光脉冲宽度较小(约1毫微秒左右);④输出脉冲峰值功率高(能达到兆瓦数量级);⑤输出波长3371埃又能在很高的重复率下工作;⑥激光器件工作可靠、寿命长、造价低.     

大气压下运转的氮分子激光器

氮分子激光器是一种结构简单又应用较广的器件。此种器件的上能级寿命很短,介质放大系数很大,其粒子数反转是通过介质放电过程中基态分子直接与高能电子碰撞激励产生的。它的输出功率主要受气体密度、电场强度、电流密度、电流脉冲的上升时间和器件的几何结构等影响。如果以上几个方面匹配恰当,会获得较大功率的脉冲输出。其中特别是气体密度一项尤为重要。因为一定体积内的受激分子数直接依赖于气     

用单块瓷体制作大气压氮分子激光器

大气压氮分子激光器不需要真空系统,简化了结构和操作,它输出的激光脉宽也比低气压时约窄一个量级,虽然脉冲能量较小,但仍可得到较高的峰值功率。已经有许多文献报道了使用双面敷铜板或自制薄膜电容的平板式、卷筒式大气压氮分子激光器,但是由于器件体积大或工作不稳定、寿命短而不利于推广应用。缩小体积、提高工作可靠性较好的方法是使用高介电常数的瓷体作介质。     

氮分子紫外脉冲激光器(下)

2.横向激励型氮激光器如前文所述,纵向氮激光器的优点是方向性好,结构紧凑,体积小。缺点是峰值功率不太大,其主要原因是用同轴电缆馈电,阻抗较大;放电管孔径较细;充气压力较低;放电管长度受到限制,一般不超过氮气的击穿速度与激光上能级辐射寿命之乘积。     

氮分子紫外脉冲激光器(上)

氮分子紫外脉冲激光器(以下简称氮激光器),于1963年问世,它的基本特征是:峰值功率大,一般在数兆瓦量级,最高已达60兆瓦;脉冲宽度窄,一般在10毫微秒左右,最窄已达0.6毫微秒;重复工作频率高,一般可达每秒几十次到一百次,最高已达1300次/秒;输出激光处在紫外波段,波长为3371埃;结构简单,制造容易,造价较低。氮激光器应用很广,它所发出的3371埃紫外光广泛应用于泵浦染料激光器及激光光谱、污染探测、集成光学、农业育种、癌症诊断、石油勘探等方面。     

模向激励大气压氮激光器

本文介绍一种结构简单的横向激励大气压(TEA)氮分子激光器。氮气在腔内自由流动,使用一个增压同轴火花隙,当工作电压为15千伏时获得激光输出峰功率约为0.4兆瓦,脉宽小于2毫微秒。激光波长为3371埃。本文还初步讨论传输线形状、激光腔与开关火花隙电感、劈形电极距离对激光输出的影响。     

氮分子激光器

随着我国激光新技术在工农业生产中日益广泛的应用,对激光器件的研制提出了更高的要求,产品的数量远远不能满足日益增长的需要,品种更落后于生产的发展,特别在全国人民大办农业的大好形势下,广大科技人员与贫下中农相结合开展科学种田,激光育种已初见成效,同时要求更多品种、不同能量、不同波长的激光器件,为育种提供更多实验条件.     

紫外氮分子激光器研究

本文根据氮分子激光器原理和Blumlein结构横向放电脉冲激光器的电路原理,分析各种参数如激光腔电感、电极形状、火花隙电感、传输线以及在激光器中放电开始点对激光输出的影响。研制成一种结构紧凑小型的氮激光器,此种器件最适宜作染料激光器的泵浦光源。     

A pulsed N2O waveguide laser with extended tunability

An air cooled N₂O waveguide laser with pulsed longitudinal DC excitation is described. It can oscillate in 70 lines, and, at a pressure of 80 mbar, it can be tuned single line and single mode over a tuning range of 350 MHz in a number of stronger lines. The laser performance is studied for different gas mixtures, involving He, N ₂, and CO, and for various resonator configurations and cooling schemes. Operation at the required pressure is possible only if CO is used in the gas mixture. The potential of the laser for Doppler limited spectroscopy is illustrated through measurements of NH₃      

双面预电离N_2激光器

在双层平板电容 Blumlein 系统激发的 N_2激光器中,采用简易的双面预电离方法(四电极激光器)提高了 N_2激光器的输出稳定度与输出功率。     

紧凑式分段TEA N_2激光器

本文叙述了以Blumlein电路分段激发的结构简单紧凑的TEAN_2激光器的特性。研究了电容与电晕预电离对激光输出功率的影响。     

Scaling of laser power with N2 partial pressure in aconvective-cooled CW CO2 laser

Diffusion-cooled and convective-cooled CW CO₂ lasers have significantly different N₂ partial pressure in their optimum laser gas mixture. While in diffusion-cooled lasers the N₂ fractional concentration is normally within 20% of the total gas pressure, it ranges up to 60% in convective-cooled lasers. By considering various effects of N₂ and solving a simplified rate-equation model analytically, the large difference in the optimum N ₂ concentrations in these two types of CO₂ laser is explained     

添加气体对TE N2激光器输出的影响

本文给出了在纯N2中添加SF6和He气对TEN2激光器3371Å输出影响的实验结果。实验结果表明,在纯N2中添加少量SF6,可使激光输出增加一倍,而添加2～3倍He气,可提高输出功率30%～7倍。本文研究艺了添加He气对混合气体电子温度、电子密度和电子能量分布的影响,从而合理地解释了加He气可以提高输出功率这一实验结果。     

混合染料在N_2激光泵浦下的光辐射

考察了一些混合染料的乙醇溶液在N_2激光泵浦下所发射的光谱.这些混合染料分别是Rh6G加甲酚紫、RhB加甲酚紫、Rh6G加RhB以及Rh6G加RhB加甲酚紫.讨论了其中的能量转移过程.证实混合染料对拓宽激光可调谐范围、提高某些染料的激光效率以及获得双波长激光振荡是可行的.     

氮气或氧气气氛退火的氧化铪材料电荷泄漏情况研究

本文中, 使用开尔文探针显微镜,研究了不同退火气氛(氧气或氮气)情况下氧化铪材料的电子和空穴的电荷保持特性。与氮气退火器件相比,氧气退火可以使保持性能变好。横向扩散和纵向泄露在电荷泄露机制中都起了重要的作用。 并且,保持性能的改善与陷阱能级深度有关。氮气和氧气退火情况下,氧化铪存储结构的的电子分别为0.44 eV, 0.49 eV,空穴能级分别为0.34 eV, 0.36 eV。 最后得到,不同退火气氛存储器件的电学性能也与KFM结果一致。对于氧化铪作为存储层的存储器件而言,对存储特性的定性和定量分析,陷阱能级,还有泄漏机制研究是十分有意义的。     

N2 effect on GaAs etching at 150 mTorr capacitively-coupled Cl2/N2 plasma

The role of N₂ on GaAs etching at 150 mTorr capacitively-coupled Cl₂/N₂ plasma is reported. A catalytic effect of N₂ was found at 20-25% N₂ composition in the Cl₂/N₂ discharges. The peak intensities of the Cl₂/N₂ plasma were monitored with optical emission spectroscopy (OES). Both atomic Cl (725.66 nm) and atomic N (367.05 nm) were detected during the Cl₂/N₂ plasma etching. With the etch rate and OES results, we developed a simple model in order to explain the etch mechanism of GaAs in the high pressure capacitively-coupled Cl₂/N₂ plasma as a function of N₂ ratio. If the plasma chemistry condition became positive ion-deficient at low % N₂ or reactive chlorine-deficient at high % N₂ in the Cl₂/N₂ plasma, the GaAs etch rate is reduced. However, if the plasma had a more balanced ratio of Cl₂/N₂ (i.e. 20-25% N₂) in the plasma, much higher etch rates (up to 150 nm/min) than that in pure Cl₂ (50 nm/min) were produced due to synergetic effect of neutral chlorine adsorption and reaction, and positive ion bombardment. Pure Cl₂ etching produced 14 nm of RMS surface roughness of GaAs. Introduction of ?20% N₂ gas in Cl₂/N₂ discharges significantly reduced the surface roughness to 2-4 nm. SEM photos showed that the morphology of photoresist mask was strongly degraded. Etch rate of GaAs slightly increased from 10 to 40 nm/min when RIE chuck power changed from 10 to 150 W at 12 sccm Cl₂/8 sccm N₂ plasma condition. The surface roughness of GaAs etched at 12 sccm Cl₂/8 sccm N₂ plasma was 2-3 nm.     

无He高速流动CO_2激光器的研究

用一个开环流动装置研究了无He混合气的放电CO_2激光输出特性,获得1400W的输出,电光效率～5％,并建立了流动条件下的分子动力学模型,分析计算了小讯号增益、气压、密度、流速、温度等参数沿流场的分布。     

TEA序列带CO2激光器的实验研究

Using an in－cavity hot CO₂ cell that is shorter than a TEA CO₂ discharge length,conversion characteristic of a TEA CO₂ laser operating on sequence bands is studed.Choosing proper operation conditions,output can be attained on more than 40 sequence lines and the output energy per pulse exceeds 1J on more than 10 lines.