YAG:Nd~(3+)激光器在工业加工中的应用及参数选择

本文概述了YAG:Nd~(3+)激光器在工业加工中的几种应用。对YAG:Nd~(3+)激光器在不同应用中,根据不同的加工要求,合理地选择激光参数和加工参数的问题作了介绍。     

某些双原子氟化物分子激光发射谱的近似计算

本文给出了双原子氟化物分子激光发射谱的经验公式,并作了验证,也估算了其它几种介质可能的激光发射谱分别为98.07nm/HeF,118.29nm/NeF,457.44nm/RnF,和683.99nm/AtF。     

激光辐照对冷冻精子活率和活力的影响

分别用7.48J/cm~2和14.96J/cm~2能量密度的氦氖激光辐照23份液氮冷冻前人的精液,冻贮三个月后复温查精子活率和毛细管穿透高度。结果:经7.48J/cm~2剂量的激光辐照后的精子活率和穿透高度明显提高,分别平均提高10.18％和8.32mm,与未受辐照组比较差异显著(P<0.05)经14.96J/cm~2辐照组,活率较未照组降低。实验结果说明适当剂量的激光辐照能够增强精子对冷冻的耐受力,提高精子的复活率和活动力。     

延迟线解调光PSK信号时的量子噪声谱

本文分析了延迟线法解调光PSK信号时的量子噪声谱,讨论了检测条件、信号传输速率等对量子噪声的影响。     

大功率激光功率密度分布的简易测试

本文提出一种测量连续输出大功率红外激光功率密度分布的实用方法,并详细分析其物理机理。     

低剂量CO_2激光对茄子种子活力影响的研究

低剂量激光照射种子对其发芽率、发芽势、酶活性均有一定的刺激效应。郝丽珍等曾在青椒上作过研究。本文在茄子上也得到了类似的结果,进而为蔬菜种子播前处理提供了依据。 1 材料和方法 茄子品种为七叶X紫茄,含水量为8.33％,试验均选用饱满的大小均一的中等种子。将种子置于自制的种盘内照射,CO_2激光扩束后功率为4.05W,光斑直径为2.5cm,照射距离为     

脉冲He—Ne激光用于斜弱视治疗

本文介绍了脉冲He-Ne激光治疗儿童斜弱视的光电原理、治疗方法与临床应用。     

聚合物PTC材料的研究与应用

对聚合物ＰＴＣ材料ＰＴＣ现象的几种解释作了介绍，着重讨论了其导电机制、影响电性能的主要因素及其在自动限温和过电流保护等领域的应用，简要说明了它的几种制作方法，并对当前该领域的发展趋势和最新研究开发进展作了较详细的介绍。     

Some observations from interrupted lifetest of GaInAsP/InP inverted-rib laser diodes

Conventionally, lifetests of semiconductor laser diodes usually involved operating the devices continuously at either constant power output or drive current, with periodic recording of their characteristics. In this paper, some effects arising from interrupted lifetest of 1.3 m GaInAsP-InP inverted-rib laser diodes are reported. This unconventional lifetest method involves constant power biasing at 4 mW/facet and 8 mW/facet respectively at 50°C, followed by a period during which the lifetest is interrupted and the devices left unbiased at room temperature. Subsequently, the devices were put back on constant power biasing at 50°C. Among a number of parameters, pronounced reduction in the threshold current, current for 4 mW/facet and 8 mW/facet were observed, indicating strong recovery effects commencing from the time when the life-test was interrupted. Redistribution of mobile defects in the cladding layer is postulated to be the cause of the degradation recovery, and the data supports the occurrence of an aging-current dependent defect annihilation mechanism. Such recovery effects have so far been observed to occur only in the GaInAsP-InP inverted-rib devices.     

单纵模激光的再生放大

调Ｑ激光器的输出单纵模脉冲经衰减和削波后，被注入到一Ｎｄ∶ＹＬＦ调Ｑ副腔里，注入脉冲能量１．２ｎＪ，放大以后的脉冲能量１．５ｍＪ，增益达１０６；脉宽由６ｎｓ压缩到４．５ｎｓ。实验和理论分析均表明，当注入信号脉宽短于放大器腔来回一周的时间时，副腔对单纵模激光的放大是一种再生放大行为，单纵模激光的再生放大消除了注入锁定中苛刻的腔长匹配要求。