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用美国光谱物理公司生产的四倍频Nd∶YAG调Q脉冲激光器,激光输出波长在1064 nm时最大输出能量为1500 mJ,532 nm时为800 mJ,532 nm时为475 mJ ,266 nm时150 mJ.脉冲宽度8 ns, 激光重复率10 Hz;打孔材料为Ni-Go基超合金Inconel-718.这种合金材料除了Ni、Go以外,还含有Cr,Fe,Mo,Ti,Al,Cd和C等.
我们使用短脉冲的4个不同波长的激光对718合金进行打孔,研究了不同波长、不同激光能量和不同透镜焦距对打孔速率和质量的影响.实验表明,在其它条件不变的情况下,存在最佳激光能量和透镜焦距;激光的波长越短,打孔的速率越快同时打孔的质量也越好,即;短波长激光打孔时,孔周围的再铸层和微裂纹明显减少;并讨论了激光与镍钴基超合金作用时的物理现象.(OE8) 相似文献
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研究不同工作参数下几种波长的激光对离体猪心经外膜打孔的组织学变化,寻找适合心外膜打孔的激光源及最佳工作参数.用自制的波长1320 nm和1060 nm的Nd∶YAG激光,532 nm KTP倍频Nd∶YAG激光,以多种工作参数对离体猪心经外膜激光打孔,与进口的波长2100nm的Ho∶YAG激光比较.
在类似工作参数下,KTP倍频Nd∶YAG激光与目前应用的Ho∶YAG激光类似,能以较少的触发次数形成激光孔道,且所形成的孔道具有热损伤小的优点.(OF9) 相似文献
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为了有效提高激光打孔的速率和激光能量的利用率,采用长脉冲激光和短脉冲激光空间叠加打孔的方法,对复合激光打孔的最佳匹配参量进行了理论和实验研究。建立复合激光打孔最佳匹配模型,以熔融物的产生和去除达到平衡为准则,理论计算得出长脉冲激光和短脉冲激光的最佳匹配参量和最佳匹配情况下的复合激光打孔速率。同时进行了毫秒脉冲和纳秒脉冲的Nd:YAG激光器复合作用于5mm的不锈钢板的打孔实验。结果表明,在实验中得到的最佳匹配参量下,复合激光打孔速率相比于毫秒脉冲激光单独打孔最大提高了3.3倍。实验和理论模型均证明了复合激光打孔在最佳匹配状态下,打孔速率达到最大,激光能量得到充分利用。 相似文献
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研究在空气中使用1.06μm YAG激光诱导放电打孔的方法。在不同的放电脉宽下进行激光诱导放电打孔的实验,比较了激光打孔和激光诱导放电打孔两种方法,指出了激光诱导放电打孔的优点。 相似文献
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KTP倍频Nd:YAG激光和Ho:YAG激光心肌打孔组织学变化的对比研究 总被引:4,自引:0,他引:4
目的 :比较国产 KTP倍频 Nd:YAG激光和 Ho:YAG激光对离体猪心激光打孔的组织学效应 ,探讨国产 KTP倍频 Nd:YAG激光用于激光心肌血运重建术的可能性。方法 :分别用 KTP倍频 Nd:YAG激光和 Ho:YAG激光以多种级别的工作参数对离体猪心左心室心内膜面进行照射 ,行病理组织学检查 ,测量激光孔道直径、深度及坏死层厚度。结果 :KTP倍频 Nd:YAG激光和 Ho:YAG激光均能有效形成激光孔道 ,随能量增加 ,孔道深度增加。KTP倍频 Nd:YAG激光具有孔道直、热损伤小的优点。结论 :KTP倍频 Nd:YAG激光是激光心肌血运重建术可供选择的激光源。 相似文献
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为了研究Yb:YAG激光器的倍频输出特性,采用LD端面抽运掺杂原子数分数为0.1的Yb:YAG薄片激光晶体(4mm×1mm)、LBO(LiB3O5)腔内倍频进行了实验研究。在LD抽运功率为1.37W时,通过调节LBO的放置角度,实现了频率选择,并获得了最高功率为3.1mW的537.8nm的基模连续激光输出,光斑椭圆度为0.94。结果表明,采用Yb:YAG激光晶体,通过LBO腔内倍频可以获得稳定的高光束质量的537.8nm激光输出。 相似文献
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To explore the possibility of photodisruption in rabbit sclera by femtosecond (fs) laser and seek appropriate incision techniques and relevant parameters,a fs laser (800 nm/50 fs) with different pulse energies was applied to irradiate rabbit sclera in vitro. By moving a computer-controlled three-axis translation stage to which the sample was attached, the laser achieved three types of incisions: transscleral channel, snake pattern and linear cut. The irradiated samples were observed by light microscopy and scanning electron microscopy (SEM).In comparison with fs laser, Nd:YAG was used as control. The experimental results show that through an objective lens with numerical aperture (NA) of 0.2, the fs laser with power intensity larger than 955 TW/cm2 and pulse, energy ranging from 37.5-125 μJ, cutting depths from 30-70 μm. may be achieved after linearly scanning in sclera at a translation speed of 0.1 mm/s. However, it failed to make any photodisruption when the power intensity was below 796 TW/cm2 or the pulse energy was less than 31.25 μJ under the same condition. Compared with the Nd:YAG laser, the inner wall of the channel was smoother and the damage to the surrounding tissues was slight with the fs laser. The high precision of intrascleral photodisruption and minimal damage to surrounding tissues by a fs laser display its potential application in the treatment of glaucoma. 相似文献
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It has been demonstrated that silicon carbide (SiC) may be used as an efficient heatsinking material for intracavity face cooling of gain media in solid-state lasers. Comparative thermal modelling and temperature distribution measurements of a diode-pumped 4% Nd:YAG ceramic laser medium face cooled by undoped YAG (as a baseline), diamond and SiC lead to the belief that SiC is an effective replacement for much more expensive diamond in this application. Laser performance of a SiC face-cooled 4% Nd:YAG ceramic press-fit stack without AR coatings was demonstrated to have 24% slope efficiency 相似文献
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