However , to suppress high order modes , bending multimode fiber will bring additional power wastage , which will affect the output characteristics of fiber amplifiers and fiber lasers , such as the gain and pulse energy 对多模光纤采取弯曲来抑制高阶模的方法带来了额外的功率损耗,这个额外的损耗对光纤放大器的增益以及输出的激光脉冲能量都会造成影响。
In this thesis , the fabrication , characteristics and applications of the novel long - period fiber gratings ( lpfgs ) induced by focused high - frequency co2 laser pulses are studied . the main work is summerized as follows : 1 该方法利用高频脉冲的热冲击效应，由于脉冲能量集中，单个脉冲加热时间短，因此加热效率高，能高效率高质量地写入低成本的长周期光纤光栅。
It has been confirmed practically that the diamond highness above base material can be adjusted with the range when the generator is put into use , and the result shows that the current density drop sharply with the increase of machining gap 结果表明，间隙值的扩大伴随电流密度的显著下降，检测电解电流控制脉冲能量的方法对实现电蚀层厚度基本可控是可行的，可让金刚石突出一定高度。
The models ’ simulation show that single mode operate in fiber amplifier at the core radii is 32 m , when the output pulse energy is to 2 . 69mj . compared with single mode fiber amplifier , the output pulse energy is more than 2 orders 通过数值仿真,我们得到了纤芯为32 m时,放大器仍然能够保持单模运转,此时输出的单脉冲能量达到2 . 69mj ,比传统的单模光纤放大器所能提取的脉冲能量大两个量级。
Some analytical expressions of fcps , such as frequency gravity , pulse energy , etc . have been calculated , beginning with the description of pulse electric field . range of the influences of carrier phase is analyzed subsequently , both in the time and frequency domain 从脉冲电场的表达式出发，计算得到几周期脉冲平均频率、脉冲能量等参量的解析表达式，在此基础上，分别从频域和时域分析了载波相位的作用大小和范围。
In the two - photon resonance case , part of the input pulse energy is transformed into higher and lower frequency components through amplified spontaneous emission and four - wave mixing , and the medium shows strong optical power limiting effect 在双光子共振情况下，即入射脉冲频率等于1 、 3能级之间的共振频率的一半，由于介质中放大的自发辐射和四波混频的作用，部分入射脉冲能量转化为高频和低频电场成分的能量，分子介质表现出了很强的光功率限幅特性。
Are concerned the theoretical analysis and experiment research on diode - end - pumped and diode - side - pumped nd : yag lasers , and e - o q - switched technologies . the diode - pumped e - o q - switched pulse solid - state laser is studied , and the 1 u j of output energy at 1 . 064 u m of less than 40ns pulse width laser is obtained 研制出一台“二极管泵浦电光调q的脉冲固体激光器” ，激光输出波长为1 . 064 m ，脉宽宽度小于40ns ，单脉冲能量约1微焦，输出模式为tem _ ( 00 )模。
With an experimental system built and two different switches designed by ourselves , a serial of high - energy high - coulomb repetitive experiments were performed at voltage up to 100kv , peak current up to 85ka , charge transfer up to about 0 . 6c per pulse , repetition rate up to 10hz , and single shot energy up to 5kj 建立了一个高平均功率开关实验系统，设计和实验了两种实用的三电极重复频率气体开关。实验获得的最大工作参数为：工作电压100kv ，峰值电流85ka ，电荷传递量0 . 6c脉冲，重复频率10hz ，单脉冲能量5kj 。
Shapes of pulse envelope are found to have some effect on the degree of phase influences . dependence of single - cycle pulse ( scp ) energy on the carrier phase has been studied for gaussian , lorentzian , hyperbolic secant and sine shapes respectively , which shows that these energies can be expressed in the same form . phase effect on pulse with gaussian envelope is the first to show , then are hyperbolic secant and lorentzian pulses , and sine the last 包络对载波相位的作用范围也是有一定影响的，我们对高斯、洛仑兹、双曲正割和sinc四种不同包络的脉冲，研究了单周期脉冲能量随载波相位的变化规律，发现以上四种脉冲的归一化能量均可在形式上用同一表达式表示，并发现对于这四种不同包络的脉冲，高斯脉冲相位的作用最早体现出来，然后是双曲正割和洛仑兹脉冲， sinc脉冲最迟。
( 5 ) the intensity and s / b of libs are investigated in detail at the different buffer gas , gas pressure , and laser power . the results show that under the 120 mj laser energy , for ar the best s / b is at 200 torr pressure , but for air at 100 torr and he at 300 torr . duration of atomic spectra in ar is longer than that in air ( 5 )实验测定了不同的缓冲气体和气压以及不同的入射激光脉冲能量对原子谱线强度和背景光的影响，结果显示在氩气环境下，当气压约为200torr 、激光的能量约为120mj时， libs的s b最大；在空气和氦气中获得最佳s b时的气压约分别为100torr和300torr ；原子谱线在氮气环境中持续的时间要比在空气中持续的时间长。
