连续Nd:YAG激光器输出功率曲线双峰结构的理论与实验研究

本文分析了内含热透镜平行平凹谐振腔的性质在运行中的变化 ,以屈光度划分了稳区及非稳区 ,并根据稳区分布的对称性及稳腔和非稳腔的性质 ,分析了腔的损耗随泵浦功率的变化关系 ,进而对连续平行平凹腔的Nd :YAG激光器的输出功率特性作了详细分析。实验观测到了输出功率曲线的双峰结构 ,且测得的实验结果与我们的理论分析相一致。

连续Nd∶YAG激光器输出功率曲线双峰结构的消除

运用激光谐振腔理论详细分析了不同腔参数下激光腔的稳定特性,进而分析了激光器的输出功率曲线,结果表明在三种特殊腔参数下,激光器的输出功率曲线不产生双峰结构,且其中的两种具有较大的动态运行稳定范围;在理论分析的基础上,我们设计了腔参数,并进行了实验,且实验结果与理论分析相一致。

High peak power laser-diode-pumped passively Q=switched Nd:YVO_4/Cr^(4+):YAG laser

In this paper, we report a high peak power passively Q-switched laser-diode-end-pumped Nd:YVO_4/Cr^(4+):YAG laser polarized along the C axis, generating 4.23-W average power and 18-kW peak power (144-μJ pulse power) with 8.0-ns time duration (29.4-kHz repetition rate) at 1064 nm while the pump power is 21.2 W.

High peak power subnanosecond pulse characteristics with different wall structured CNTs in a doubly QML Nd:Lu_(0.15)Y_(0.85)VO_4 laser

By simultaneously employing both an electro-optic modulator and carbon nanotube saturable absorber(CNT-SA)in a dual-loss modulator, a subnanosecond single mode-locking pulse underneath a Q-switched envelope with high peak power was generated from a doubly Q-switched and mode-locked(QML) Nd:Lu_(0.15)Y_(0.85)VO_4 laser at1.06 μm for the first time, to our knowledge. CNTs with different wall structures—single-walled CNTs(SWCNTs),double-walled CNTs(DWCNTs), and multi-walled CNTs(MWCNTs)—were used as SAs in the experiment to investigate the single mode-locking pulse characteristics. At pump power of 10.72 W, the maximum peak power of1.312 MW was obtained with the DWCNT.

Nd∶YAG脉冲激光焊接TC4时峰值功率、脉宽对焊缝成形的影响

采用Nd∶YAG脉冲激光作为焊接热源,对TC4钛合金进行平板拼焊焊接实验,并结合焊接过程中产生飞溅的情况、焊缝表面宏观形貌颜色的变化情况及熔深熔宽的变化情况三个方面,详细分析了峰值功率和脉宽对焊缝成形的影响。实验结果表明:其他工艺参数一定时,满足焊缝表面基本无氧化的峰值功率——脉宽关系图呈近似"直角三角形";当峰值功率一定时,随着脉宽的增加,熔深和熔宽均增加,当脉宽一定时,随着峰值功率的增加,熔深和熔宽也均增加,且两种情况下熔深的增幅均大于熔宽的增幅。