Discharge Pumped Rare-Gas Excimer Lasers in Vacuum Ultraviolet Spectral Region

真空紫外光谱区放电泵浦稀有气体准分子激光器

基本信息

批准号：
04805037
负责人：
SASAKI Wataru
金额：
$ 1.22万
依托单位：
Miyazaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04805037/
关键词：
Rare gas excimer rare gas cluster Vacuum ultraviolet Discharge pumping Xe excimer 希ガスクラスターレーザー真空紫外

项目摘要

Rare gas excimer lasers are atractive vacuum ultraviolet sources with high power tunable output around the center of their spectra. However, their oscillation have been obtained only by electron beam pumping. The electron beam pumped rare gas excimer lasers have difficulties for applications because of their low repitition operation. It, therefore, has been desired the rare gas excimers were considered to produce by three body collisions of an excited rare gas atom with two of ground state atoms. In this case a high pressure operation is favorable, because a formation rate of raer gas excimers is proportional to the square of the gas pressure. It is well known that uniform glow discharges in the high pressure gas are very difficult to establish. We have proposed a new concept of formation of the rare gas excimers in which the rare gas excimers were formed from rare gas clusters in an expanding jet discharge.In this project it has been experimentary confirmed that Xe excimers were forme … More d from the Xe clusters excited by discharge electrons. Distributions of sizes of the Xe clusters were measured with a TOF spectrometer by three photon ionization of the clusters. Densities of the Xe dimers were measured to be 10^<17>cm^<-3> at 3mm down stream of the expanding jet with 3atm.to 8atm.of staggnation pressures. Densities of Xe excimers were measured to be 10^9cm^<-3>, the densities of the clusters were 10^<17>cm^<-3> though. These very low efficiency of excimer formation from the clusters is considered to be unsuitable discharge conditions.In DC sischarges radiative transitions from the ^3SIGMA excimer state were predominant, stimulated emissions, therefore, were not observed because the stimulated emission cross section of ^3SIGMA state was three orders smaller than that of ^1SIGMA state. As a result it is considered that fast pulsed discharges should be essential for obtaining a high laser gain.It is very important to point out that an efficinet vacuum ultraviolet lamp can be produced using the excimer radiation by the ^3SIGMA transitions.In future electron energy dependences of the excitation cross sections of rare gas excimers from the clusters will be measured in order to conclude efficient discharge conditions. Less

稀有气体准分子激光器是一种有吸引力的真空紫外光源，在其光谱中心附近具有高功率可调谐输出，但是，它们的振荡只能通过电子束泵浦来实现，因为它们的功率低，因此难以应用。因此，希望稀有气体准分子通过激发的稀有气体原子与两个基态原子的三个体碰撞来产生，在这种情况下是高压操作。是有利的，因为稀有气体准分子的形成速率与气体压力的平方成正比。众所周知，在高压气体中建立均匀的辉光放电是非常困难的。稀有气体准分子，其中稀有气体准分子是由稀有气体团簇在扩展的喷射放电中形成的。在该项目中，实验证实Xe准分子是由放电电子激发的Xe团簇形成的。 Xe簇的尺寸通过TOF光谱仪通过簇的三光子电离来测量。在3atm的膨胀射流下游3mm处测量Xe二聚体的密度为10^ 17 cm^ -3 。 Xe准分子的密度被测量为10^9cm^-3，即Xe准分子的密度。然而，簇的尺寸为 10^<17>cm^<-3>，这些簇形成准分子的效率非常低，被认为是不合适的放电条件。在 DC sischarges 中，来自 ^3SIGMA 准分子状态的辐射跃迁是主要的受激发射，因此，没有观察到，因为 ^3SIGMA 态的受激发射截面比 ^1SIGMA 态小三个数量级，因此认为是快脉冲。放电对于获得高激光增益至关重要。需要指出的是，可以使用^3SIGMA跃迁的准分子辐射来产生高效真空紫外灯。未来电子能量对稀有气体激发截面的依赖性将对簇中的准分子进行测量，以确定有效的放电条件。