闪光灯泵浦的掺钛宝石激光器研究

报道了闪光灯泵浦的掺钛宝石(Ti~(3+):Al_2O_3)可调谐固体激光器的实验结果。已获得激光输出能量51mJ/脉冲,激光效率大于0.1％,可调谐范围为700—900nm。讨论了改善该激光器性能的途径。     

Theoretical study of quasi-phase-matching fourth harmonic generation in periodically poled lithium tantalate

The direct fourth harmonic generation (FHG) is theoretically demonstrated based on quasi-phase-matching (QPM) configuration in periodically poled lithium tantalate (PPLT). The wavelength dependence of the period of FHG QPM gratings is calculated. Bandwidths of fundamental wavelength, temperature, and incident angle are also studied. A very wide bandwidth, as large as 119.5 nm, of fundamental wavelength near 3699 nm is found with the QPM period of 9.442 μm and the crystal length of 1 cm.     

I型准相位匹配周期性极化铌酸锂倍频蓝光输出

在周期为 14 .5 μm的周期性极化铌酸锂中 ,利用d3 1,得到了一阶I型EωYEωY-E2ωZ (oo-e)准相位匹配蓝光二次谐波。在 15 0℃下 ,由 114 μJ抽运光 ,得到了 5 2 μJ ,0 .4 73μm倍频蓝光 ,对应于平均最大转换效率 4 5 .6 %。制备了一阶和三阶周期分别为 4 .5 μm和 13.5 μm的周期性极化铌酸锂。在EωZEωZ-E2ωZ (ee -e)准相位匹配 0 .4 73μm蓝光倍频中 ,15 0℃下 ,分别得到了 4 1.3%和 19%的倍频转换效率。oo -e准相位匹配比传统的ee -e准相位匹配有较大的光栅周期 ,尤其在短波长区域倍频输出应用中 ,降低了周期性结构制作的困难 ,其较大的容许带宽在实验中提高了频率转换效率。实验结果表明了在周期性极化铌酸锂中准相位匹配倍频的偏振相关性。     

Generation of the numerator=2 rational harmonic mode-locked pulses in fiber ring lasers

In conventional rational harmonic mode-locking, optical pulse trains with the repetition rate of (pn+1)f_c are generated when the modulation frequency of the in-cavity modulator is set at f_m = (n+1/p)f_c, where n and p are both integers, f_c is the fundamental cavity frequency. In this paper, we report that rational harmonic mode locking phenomenon takes place in the fiber lasers when the modulation frequency is set at f_m =(n+2/p)f_c. The pulse generations are experimentally demonstrated when the numerator of the rational corresponds to 2 in 5th and 7th order rational harmonic mode-locking.     

Nile Blue等染料中的简并四波混频和位相复共轭特性

对Nile Blue等三种新型染料进行了简并四波混频位相求共轭实验。泵浦光强远大于介质饱和光强时,观察到后向波反射率随染料浓度改变出现振荡。后向波反射率与探测光强度成反比。这些结果通过一些理论计算得到了解释。     

周期性谐振腔的稳定性

详细分析了一般周期性谐振腔的稳定性，发现对一每周期合ｍ根激光棒的Ｎ周期谐振腔，共存在ｍ个稳定区，并在每一稳定区内存在（Ｎ—１）个奇异点，在这些奇异点处，谐振腔处于介稳状态，对失周期性很敏感；另外，还讨论了周期性谐振腔的热稳条件问题。     

OF和NF气体激光新体系

用常态下稳定的气体分子和稀有气体卤化物准分子作为激光工作物质已被广泛和深入地研究,其中有一些已成为实用的商品器件。对在特殊状态下产生的不稳定二原子、三原子以及多原子体系的探索工作一直在开展着。虽然在自由基家族中已有OH、CN、CO实现了激光输出,然而,真正实用的体系还有待进一步研究。从Diegelman等人偶然发现了CLF交叉卤素激光以来,曾有一度对三原子准分子体系在卤素及惰性气体之间进行了探索。从目前所发现的激光工作物质来看,在适当的条件下,每一种双原子分子都有可能实现激光输出,因此对双原子自由基的探索工作将是有意义而富有成果的。     

同轴脉冲闪光灯泵浦的掺钛宝石激光器研究

本文叙述了我们用自制的同轴脉冲闪光灯泵浦的掺钛宝石激光器实验装置和实验结果,用电极间距8厘米的同轴闪光灯泵浦φ7×70mm掺钛宝石棒,已获得激光输出300mJ/脉冲,激光效率0.1％,讨论了进一步提高激光效率的方法。     

Generation of broadband and multiple-peak THz radiation in aperiodically poled lithium niobate

Terahertz (THz) regime has become the most attracting frequency range in the electromagnetic radiation in re- cent years[1-3]. Single-cycle THz waves intrinsically pos- sess a broad bandwidth[1]. Unfortunately, the generated THz waveform is very weak and inhomogeneous for the THz frequency. It has been proved experimentally[2-4] that the velocity mismatch between the THz pulse and the optical femto-second pulse in the periodically poled lithium niobate (PPLN) allows the generation of ult…     

K_2分子2~3∏_g—1~3∑_u~+漫射谱强度的碰撞诱导增强效应

用4415.6ACW激光线获得了5730A附近的K_2分子2~3∏_g—1~3∑_u~+漫射荧光谱。实验研究了缓冲气体Ar气压强P对漫射谱峰值强度I_(diff)的碰撞诱导增强效应。用稳态碰撞模型描述了C~1∏_u—2~3∏_g间的能量转移过程,推导出了I_(diff)-P函数关系,对实验数据进行了令人满意的拟合。这种拟合表明:适当变更实验装置,利用本文模型可以得到C~1∏_u—2~3∏_g间的能级交叉速率和碰撞诱导转移速率。