氧碘化学激光器运行模式对其脉冲化影响的模拟研究

根据氧碘化学激光器的反应机理建立了一维预混脉冲出光理论模型,从理论上研究了气体总压力在660-2660 Pa, 温度在150-400 K区间内对单脉冲能量、脉宽和峰值功率的影响.分析了气体总压和温度对出光特性影响的内在原因. 计算结果表明:增益介质温度对单脉冲能量的影响要远大于对激光脉宽的影响;增益介质温度在150 K, 气体总压在1330 Pa可以获得比温度在400 K,气体总压为2660 Pa时更高的峰值功率. 因此在不干扰超音速流动状态条件下瞬间大量产生碘原子,可以实现高效的脉冲氧碘化学激光器.     

超音速化学氧碘激光器光腔扩张角

 在超音速化学氧碘激光器的设计中,为了削弱光腔部分的化学反应放热对激光器出光的负面效应,在光腔部分通常加入一扩张角。为了研究这一扩张角对激光器内流场的作用,根据kW级超音速化学氧碘激光器的实验平台,数值模拟了激光器内超音速混合喷管至光腔部分的流动过程,解析了光腔扩张角对内流场的流动参量和化学增益的影响,从维持压强和温度稳定性方面比对分析了不同扩张角度的性能,并探索了喷管高度和扩张角之间的规律。结果表明：此kW级超音速化学氧碘激光器的合理光扩张角度为4.5°。     

连续波氧碘化学激光器小信号增益的测量

描述了利用脉冲光解碘原子激光器作为探测激光器测量连续波氧碘化学激光器小信号增益的方法与装置,给出了增益的测量结果,对实验结果和误差作了简单讨论。     

LaMgAl11O19:Co2+被动调Q铒玻璃激光器研究

综述了被动调Q铒玻璃激光器的发展概况,推导了被动调Q铒玻璃激光器输出脉冲能量、脉宽的解析表达式,数值模拟了腔内损耗与输出脉冲能量、脉宽及峰值功率的关系以及输出脉冲能量与输入抽运能量的关系.设计了一台LaMgAl11O19:Co2 被动调Q铒玻璃激光器,实验验证了数值模拟分析结果.结果表明,腔内损耗增加将导致输出脉冲能量下降,脉宽变大,从而峰值功率降低.输入能量低于12 J时,输出只有单脉冲,当输入能量大于12 J时,输出会出现双脉冲.在8 J的电输入下,获得了峰值功率50 kW,2.7 mJ的1.535 tm激光输出.最后讨论了提高单脉冲能量的方法.     

化学氧碘激光器高压操作的可行性以及最佳增益区的确定

利用一简单的模型,从理论上证明了在化学氧碘激光器小信号增益存在依赖于系统总氧压力的最佳值,同时讨论了高压下工作的化学氧碘激光器的可行性,最后给出了确定化学氧碘激光器的最佳增益区的方法。     

光引发和放电引发的脉冲氧碘化学激光器

光引发和放电引发的脉冲氧碘化学激光器氧碘化学激光器具有波长短、效率高、光束质量好、高储能、装置安全简便等优点。１９７８年美国空军武器实验室ＭｃＤｅｒｍｏｔｔ等人首次实现了连续波氧腆化学激光器出光［１］．由于氧碘化学激光器具有许多潜在的应用，这种新型高...     

基于增益负反馈的COIL自脉冲方法

针对超音速化学氧碘激光器增益介质的横流特性,设计了具有增益负反馈的光学谐振腔结构,通过化学反应的超音速流场和光场的耦合仿真,根据具体的激光器运行参数,论证了这种结构实现自脉冲激光的可行性。结果表明:振荡激光在增益区上游放大次数越多,对上游增益介质能量提取能力越强,脉冲调制作用越显著。采用激光光斑缩束再放大的结构设计,脉冲激光的峰值功率提高10~20倍,从理论上证明了增益负反馈的调制方法能够实现横流激光器脉冲激光输出。     

近共振传能放热对氧碘化学激光器性能的影响

在氧碘化学激光器(COIL)中,O2(1Δ)与I的近共振传能反应是一个放热反应;它与水汽等的猝灭放热反应一样会对激射过程产生不利影响,而且是不可避免的。计算了猝灭放热效应对光腔气动特性输出功率的影响。得到了近共振传能放热的大小与粒子数反转和激射的光子数相关,即与光腔内的增益、光场强度分布成正比,故主要发生在激光器的上游区前半部分。模型计算表明,其影响程度大致相当于7%水汽所致的对氧碘化学激光器的影响。完善了氧碘化学激光器理论计算模型。     

LaMgAl_(11)O_(19)∶Co~(2+)被动调Q铒玻璃激光器研究

综述了被动调Q铒玻璃激光器的发展概况,推导了被动调Q铒玻璃激光器输出脉冲能量、脉宽的解析表达式,数值模拟了腔内损耗与输出脉冲能量、脉宽及峰值功率的关系以及输出脉冲能量与输入抽运能量的关系。设计了一台LaMgAl11O19∶Co2 被动调Q铒玻璃激光器,实验验证了数值模拟分析结果。结果表明,腔内损耗增加将导致输出脉冲能量下降,脉宽变大,从而峰值功率降低。输入能量低于12J时,输出只有单脉冲,当输入能量大于12J时,输出会出现双脉冲。在8J的电输入下,获得了峰值功率50kW,2.7mJ的1.535μm激光输出。最后讨论了提高单脉冲能量的方法。     

基于1064nm光纤皮秒种子源的Nd:YAG再生放大器

利用Nd:YAG再生放大器,对1064 nm掺镱锁模全光纤激光器输出的皮秒脉冲进行了功率放大.研究分析了掺镱锁模全光纤激光器输出脉冲对Nd:YAG再生放大器能量提取效率的影响,通过对掺镱锁模全光纤激光器自相位调制的控制,减少了输出光谱的振荡结构,提高了掺镱锁模全光纤激光器对Nd:YAG再生放大器的能量提取效率,实现了对锁模全光纤激光器输出的中心波长1064.4 nm,3 dB光谱宽度0.35 nm、脉宽11 ps、单脉冲能量为3.2 nJ、频率为38 MHz的锁模脉冲的再生放大,得到输出重复频率为1 kHz,最大的单脉冲能量为1.3 mJ的皮秒脉冲.     

A frequency-doubled pulsed chemical oxygen-iodine laser

The intracavity second-harmonic generation of pulsed chemical oxygen-iodine laser radiation was investigated. A pulsed chemical oxygen-iodine laser with a maximum output energy of 6.14 mJ was used. The second-harmonic output of 0.5 mJ was demonstrated using a lithium iodate crystal. The conversion efficiency of 8% was limited by intracavity losses. Numerical simulation predicts that a conversion efficiency of 75% can be obtained with 1% intracavity losses.     

Efficient pulsed chemical oxygen-iodine laser with instantaneous generation of atomic iodine by volumetric discharge

A pulsed chemical oxygen-iodine laser (COIL) using atomic iodine generated by volumetric discharge of CH 3 I is developed and tested. COIL with a gain length of 60 cm is energized by a square pipe-array jet singlet oxygen generator with basic hydrogen peroxide pumping circulations and operated at subsonic gas flow. Maximum output energy of 4.3 J, pulse duration of 50 μs, specific energy extraction from the active medium of 2.0 J/L, and the maximum chemical efficiency of 12.5% are achieved at a chlorine flow rate of 55 mmole/s.     

Experimental investigation of chemical oxygen-iodine laser

Results of an experimental investigation of a chemical oxygen-iodine laser (COIL) are presented. We determine the factors influencing the efficiency of a chemical singlet-oxygen generator (SOG) of the bubbler type operating on the chlorination of an alkaline solution of oxygen peroxide. We describe SOG constructions. A cw COIL with output power up to 400 W is developed on the basis of the investigated SOG. The feasibility of a modular construction of high-power COIL is demonstrated. A power-output level of 1 kW was achieved with a two-section laser. The feasibility is analyzed of COIL operation in a pulsed regime by pulsed bulk accrual of iodine atoms. We show that in this regime the laser can be operated without a low-temperature trap. An advantage of such a regime is also the possibility of controlling, in a wide range, the lasing pulse duration. A strong influence of molecular chlorine on the energy content of the active medium is observed when alkyliodides are used as iodine donors. The possibilities of using a pulsed COIL for controlled thermonuclear fusion are discussed. Translated from Trudy Fizicheskogo Instituta im. P. N. Lebedeva Akademiya Nauk SSSR, Vol. 194, pp. 114–147 (1989).     

Novel concept of electric discharge oxygen-iodine laser

A novel concept of discharge oxygen-iodine laser (DOIL) is presented. The supersonic DOIL includes a discharge singlet oxygen generator (DSOG) and discharge atomic iodine generator (DAIG). The operation of DSOG is based on a fast mixing of hybrid argon plasma jet of DC electric arc and RF discharge with a neutral molecular oxygen stream. The goal of our effort is achievement of DOIL oscillations by this new discharge technique, which should provide the singlet oxygen yields exceeding 30% at the total pressures higher than 10 torr. The DAIG operation is based on a cw/pulse RF discharge dissociation of iodine donors directly inside a laser iodine injector. This method substitutes the classic dissociation of molecular iodine by energy of singlet oxygen, which saves its energy for laser generation and so can increase the laser efficiency. The laser power could be thus enhanced by up to 25% if this method is employed in a chemical oxygen-iodine laser (COIL) operation, and even 3 times in DOIL without increase in the iodine laser pumping by singlet oxygen.     

碘离解和淬灭对氧碘化学激光气动特性影响的计算

 氧碘化学激光中的水汽对其运行和性能有着重要的影响。建立了考虑淬灭的单重态氧产额和变截面定常一维流的方程组，编制了程序，采用Radicl的参数进行了计算，研究了碘离解和淬灭对氧碘化学激光气体流动特性的影响，初步分析了变截面的作用和设计考虑。     

Intracavity second-harmonic generation of chemical oxygen-iodine laser emission using a LBO crystal

Intracavity second-harmonic generation of continuous-wave chemical oxygen-iodine laser emission has been studied. A chemical oxygen-iodine laser with a maximum fundamental-wave output power of about 10 W in a concentric cavity was used. Experiments were performed for three types of optical cavities using an 1 cm LBO crystal. Second-harmonic output of 12.4 W, 6.2 W, and 5.2 W, effective extraction efficiencies of 155.0% 65.9%. and 55.3%, and single-pass conversion efficiencies of 0.615%, 0.685%, and 0.655% were obtained for the respective cavities. A comparison of these results of coupling by frequency doubling with the results of fundamental-wave output coupling of this system is also presented.     

高能超音速氧碘化学激光光束质量的测量

概述了在千瓦级ＵＲ－９０腔的氧碘化学激光实验装置上进行的光束质量测量的实验，测试结果表明。