连续动转氩离子激光器最佳气压分析

本文从Jonks—Langmuir低气压放电正柱理论出发,推导氩离子激光器输出功率和充气压力的关系,并由此求得最佳气压,讨论最佳气压的影响因素,并与实验结果相比较。     

磁约束放电激励对N_2激光输出特性的影响

对磁约束放电激励技术在N2 激光器上的应用进行了实验研究。结果显示 ,横向磁场的引入可以大大提高N2 激光的输出 ,扩展工作气压范围 ,提高最佳工作气压值。     

磁约束放电激励对N2激光输出特性的影响

对磁约束放电激励技术在N2激光器上的应用进行了实验研究。结果显示,横向磁场的引入可以大大提高N2激光的输出,扩展工作气压范围,提高最佳工作气压值。     

扁平放电管He—Ne激光器特性的研究

为了在相同放电长度内获得较大的输出功率,我们设计并研制了扁平放电管的He—Ne激光器。 测量了矩形放电管He—Ne激光器的各个参量,找出了该激光器的最佳总气压,He与Ne的最佳气压比以及最佳工作电流的范围。并测试了介质的增益系数与入射光强,泵浦电流等的关系。本文还对以上参量进行了初步的理论分析。     

快速轴流工业CO_2激光器的自动气压测控系统

简述快速轴流工业CO2激光器基本工作原理以及建立气压自动控制系统的必要性，对气压测控系统的设计原理进行了分析、并且提出实现这一控制过程的最佳设计方案。     

超小型氦氖激光器工作特性研究

本工作仔细测量了腔长30mm，内径14．5mm的超小型He—Ne激光器在不同总气压、分气压比、工作电流条件下的输出功率。得到分气压比PHe；PNe=9．7：1，总气压P=4．6torr和工作电流I=3mA的最佳工作条件。为此类激光器的应用提供了数据。     

已烷对甲基氟远红外激光器的影响

观察了在不同气压比例下C_6H_(14)对CH_3F496微米激光振荡的影响。最佳气压比是CH_3F:C_6H_(14)=1:2,与纯CH_3F相比较,远红外激光输出功率增加了53％。     

一米以上全外腔氦-氖激光器的制造工艺问题

本文讨论了两个问题:一、一米以上全外腔氦氖激光器布儒斯特角的烧结工艺.用此法布氏角的倾角误差和扭角误差可在15’以内;二、选择最佳氦氖气压比和总气压,以获得较强的输出功率.     

分段石墨放电管的结构及其性能

本文从输出功率和放电管管壁的功率负荷出发,考虑了分段石墨放电管的结构改进.介绍了采用这种新型放电管结构的氩离子激光器的性能,并对最佳气压和最佳磁场提出了定性的解释.     

栅网耦合的光泵腔式亚毫米波激光器及最佳工作气压研究

采用电感性金属网栅作为光学谐振腔的反射镜和输入输出耦合器 ,设计制作了长度分别为 10 0cm、2 0 cm和 10 cm的 Fabry- Perot腔式亚毫米波激光器。运用半经典密度矩阵理论 ,通过迭代法计算了光泵腔式 NH3分子亚毫米波激光器的最佳工作气压。在实验上测量了 TEA CO2 - 10 R(8)和 9R(16 )泵浦上述 NH3分子亚毫米波激光器的最佳工作气压。理论计算与实验结果一致。     

退火对Ar~+激光再结晶多晶硅/二氧化硅界面性质的影响

本文对CW Ar~+激光再结晶SOI结构材料进行了氢等离子体退火和CW CO_2激光退少.结果表明,两种退火方法都可以明显地降低背界面的界面态陷阱密度.氢等离子体处理对晶粒间界引入的界面态退火效果更显著,而CO_2激光辐照对应力引入的界面态退火作用更明显.     

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     

Fast plasma mixing--A new excitation method for CW gas laser

"Fast plasma mixing" is proposed as a method to generate population inversions on electronic transitions for continuous lasers. Selective excitation is accomplished by preparing collision partners for excitation in two or more separate beams. Excitation in a well-defined reaction volume and a fast flow in combination with a suitable resonator will allow the fast removal of decay products from the active volume. This pumping method will allow the operation of new CW laser systems not possible with conventional discharges and CW operation of laser systems, which at this time can only be operated as pulsed lasers. A test device has been used to study the proposed excitation method. CW operation as a fluorine laser has demonstrated the general feasibility of this method. Of special interest are molecular lasers pumped by charge or energy transfer from atomic species or by chemical reactions and excimer lasers. These lasers may offer the capability of operating CW tunable gas lasers in the visible and ultraviolet spectral regime.     

气压对横流CO_2激光器输出的影响

连续输出的对流、放电、CO_2激光器小信号增益特性随介质气压(高至780Torr)变化的实验和个别较高气压(约180Torr)器件的输出实验已有较完整数据的报道,我们将每粒子电场强度E/N和模拟简化的均匀电子密度分布区宽度d取为适当的常量,计算给出了高气压条件下的输出功率、耦合度及其变化规律,但其中对于[1]文报道的实际器件在较高气压的小信号增益的检验计算,须适当调整d的数值才能与实测相近,对于放电结构与[1]、[2]相似的器件,并不满足[3]中在不同气压均取d为同一常量的简单条件,为此,本文利用[1]、[2]已公布的     

基于1S0能级的Pr3+:ZBLAN光纤上转换紫外激光的数值模拟

在Pr3 ∶ZBLAN光纤中,运用粒子数速率方程理论,研究用586 nm和335 nm连续激光双光子激发4f组态最高能级1S0,以1S0和3F4为激光上下能级实现250 nm上转换紫外激光的动力学行为,得到阈值抽运功率、激光输出功率、斜率效率和最佳光纤长度等激光参数。结果表明,阈值抽运功率随光纤长度增加而增大,斜率效率随光纤长度增加而减小,光纤较短时,无法获得较高输出功率。掺杂浓度越大则阈值抽运功率越小,斜率效率越大。在选取的特定条件下,斜率效率最高可达16.7%。     

FM mode-locked high-pressure CW RF-excited CO2 waveguidelaser

The authors report the results from a study of a FM mode-locked continuous-wave (CW) RF-excited CO₂ waveguide laser operated at 0.25-2 atm gas pressures. It is shown that electrooptic FM modulations can be efficiently used to mode lock a CW CO₂ laser. The combination of a high gas pressure and a high modulation frequency makes it possible to generate pulses which are substantially shorter than those previously reported for CW mode-locked CO₂ lasers. A theoretical approach is used for simulation of the FM mode-locked laser. The experimental pulses of a few hundred picoseconds FWHM are considerably shorter than previously reported for CW mode-locked CO₂ lasers. The experimental results are compared with the results of numerical calculations using a frequency domain simulation model     

Continuous wave thin plate Nd:glass laser

CW (continuous-wave) operation of end-pumped four-level glass lasers is modeled to obtain expressions for threshold, slope efficiency, and figures of merit. The thermal effects ultimately limiting performance in these lasers is also discussed. Basic design consideration for optimum performance of an end-pumped CW Nd:glass laser intended for mode locking are presented. On the basis of these investigations, a CW Nd:glass laser containing a heavily doped thin phosphate glass plate as the gain material has been built. The plate was inserted into a folded cavity and pumped longitudinally by a Kr laser at 0.8 μm. With 2.5% output coupling the pump threshold and the slope efficiency well above threshold were measured to be 10.5 mW and 36%, respectively. These values agree reasonably with theoretical predictions. Experimental confirmation of the predicted thermal limiting effects are also obtained     

A simplified theory of the optogalvanic effect

We present a simple phenomenological theory of the optogalvanic effect based on the multiplication of an electron within the plasma. The dependence of the signal on current and pressure and its temporal behavior are predicted for atoms irradiated by chopped CW lasers and pulsed lasers. Experimental data obtained by pulsed lasers are presented and interpreted.     

功率提取对连续波DF化学激光器腔压的影响

为了研究功率提取对连续波DF化学激光器光腔压力的影响,基于一台小型燃烧驱动连续波DF激光器装置,进行了一系列实验,实验结果显示,随着提取功率的增大,光腔压力逐渐减小。利用一维定常流理论和光腔动力学理论,建立了从燃烧室到光腔出口的一维数学模型,得到光腔压力随比功率的变化关系曲线,取得了与实验较为一致的计算结果,从而给出了功率提取对光腔压力影响的理论解释,同时也验证了数学模型的合理性。数学模型和实验结果同时表明,从光腔中提取功率,光腔压力将有一定程度的下降,将实验条件参量代入模型计算,得出比功率为50J/g时,光腔压力比无功率输出时下降约7.4%。     

Optically pumped CW dimer lasers

Bound-bound electronic transitions in simple molecules are generally suited to realize efficient multiline laser oscillation in the visible and ultraviolet spectral region. By means of optical excitation with argon and krypton lasers, CW laser oscillation could be obtained for various homonuclear diatomic (dimer) molecules such as Li2, Na2, K2, Bi2, S2, Te2, and I2, with emission of several hundred laser lines in the spectral range of about 400-1350 nm. The principles of these lasers and the general dependence of threshold and output power on temperature, pressure, length of vapor zone, and some other parameters is discussed. To achieve satisfactory CW operation, low quenching losses for the upper laser level population and a sufficiently fast relaxation of the population of the lower laser level are necessary. Under optimum operation conditions, efficiencies up to 15 percent, multiline output powers up to 400 mW, and single line-single frequency output powers up to 200 mW were achieved. These dimer lasers are three-level laser systems. In case of coherent optical excitation, two-photon or Raman-type processes contribute to the amplification process. Due to these mechanisms the forward direction is strongly favored and in a ring laser system spontaneous unidirectional oscillation is obtained. By means of a suitable three-level model, analytical and numerical calculations of gain profiles are performed and compared with experiments. These optically pumped molecular lasers are suited for various spectroscopic and kinetic investigations, for frequency standards or as simple and efficient systems to convert pump laser radiation into other spectral regions.