利用两束超连续光干涉得到的信号,测量了透镜焦点附近飞秒激光脉冲的古依(Gouy)相移。根据得到的光谱干涉信号,利用傅里叶变换得到相对相位值。激光光束在聚焦透镜后的束腰半径可以由成像方法测得。根据测量得到的激光光束束腰半径,用非线性拟合的方法得到了古依相移曲线,拟合曲线与实验结果符合得非常好。给出了古依相位在焦点前后1 mm区域内的移动量。

We present a simple method of the spectral interference between two white light continuum spectra to measure the Gouy phase shift of the focused femtosecond laser pulses. From the spectral interference signal, the relative phase is extracted by the Fourier transform method. The minimum spot size (beam waist) of the laser pulses after the lens (focal length f=200 mm) is measured by imaging method. According to the beam radius, the curves of nonlinear fitting are drawn for comparison, which fit the data of experiments very well. The quantity of phase shift is also discussed. The result shows that this method of measuring Gouy phase shifts is available and stable.

A new physical explanation of the fringes in the high-order harmonic spectra generated by ellipticity-modulated infrared pulses is proposed, which is different from those in previous works. In this work we find that the fringes are due to the spectral interference effect induced by the two outgoing pulses with a delay, which are generated by the wave plates for ellipticity control. The visibility of interference fringes observed experimentally increases with the increase of the asymmetry of the two pulses, with the decrease of the delay and with the increase of peak intensity of the driving laser pulse. The experimental results are in good agreement with the calculated ones.

穴位激光照射疗法是一种通过低强度激光束直接照射穴位的治疗方法,具有针灸作用.阐述了激光照射机体穴位在临床应用的本质,并对其使用的光剂量和作用机理做了初步讨论和分析.

本文介绍了<激光医学>课程的内容和特点,探讨如何提高该课程的教学质量的方法和措施,总结了教学过程中的一些体会和改革尝试.

本实验在前工作的基础上,观察对实验性糖尿病兔进行两次低强度He-Ne激光血管内照射后,血中甘油三酯、总胆固醇、红细胞膜总磷脂的动态变化,分析有关参数与红细胞变形能力之间的关系,以期探讨低强度激光血管内照射影响血液流变性质的可能因素.实验结果表明,经两次激光照射后,1.第1天糖尿病兔的红细胞变形能力即见改善,4天-7天后接近注药前水平.2.与其相应,甘油三酯和胆固醇在激光照射后??天即回复至正常水平.3.红细胞膜总磷脂激光照射后渐升高,至第7天与注药前无明显差异.文章讨论了有关实验指标影响红细胞变形能力的可能性.

目的探讨 He-Ne激光照射对老龄小鼠机体内氧自由基的影响,为临床应用提供依据. 方法实验采用波长为 632.8 nm的 He-Ne激光. 30只 14月龄的昆明种老龄小鼠随机分为 A组、B组、C组和D组4个组; A、D组各 8只鼠, B、C组各 7只鼠; A、B、C组为实验组, D组为老龄对照组.另 8只 6～ 7周龄相同昆明种小鼠作为青龄对照 (E)组.以能量密度为 4.68、 12.48和 18.72 J/cm2的 He-Ne激光分别照射 A、B、C3组小鼠的肝区, D、E组鼠不照射激光.照射后观察超氧化物歧化酶 (T-SOD)、Cu, Zn-SOD、Mn-SOD、谷胱苷肽 (GSH)、丙二醛 (MDA)等指标的变化. 结果能量密度为 4.68、 12.48和 18.72 J/cm2的低强度 He-Ne激光可提高 Cu,Zn-SOD、 Mn-SOD及总 SOD活性,提高 GSH含量,降低 MDA含量.其中尤以能量密度为 18.72 J/cm2的激光照射的效果最为显著,使老龄小鼠以上各项指标恢复接近正常青龄组水平. 结论 He-Ne激光照射可以提高机体抗氧化酶的活性和抗氧化剂的含量,增强机体抗氧化能力.

本实验将卵巢切除后的24只成年雌性兔分为4组,分别为A:卵巢切除组、B:雌激素治疗组、C:He-Ne激光血管内照射组、D:雌激素加He-Ne激光血管内照射组,分别测定其血液粘度等6项血液流变学指标.研究比较雌激素与低强度He-Ne激光血管内照射对去卵巢雌兔血液流变学的影响,为两者对绝经后妇女心血管疾病防治的临床使用提供参考.结果表明:雌激素可改善部分血液流变学指标;激光血管内照射使6项血液流变学指标均明显改善;雌激素加激光血管内照射共同作用与单独用激光血管内照射的结果大致相同.提示临床He-Ne激光血管内照射可阶段性替代雌激素应用于改善血液流变性,以便减少雌激素的剂量,降低其副作用.

研究了热起伏、场零点飘移和自发辐射对半导体激光器AM和FM噪声的影响。