【作者】 段雪松；

【导师】 周忠祥；

【作者基本信息】 哈尔滨工业大学 ， 光学， 2006， 硕士

【摘要】 本文研究的是激光照射金膜时其透射光和反射光的光强随时间非线性变化的现象。金膜是用真空镀膜的方法镀在玻璃基底上,厚度是50-60nm,玻璃基底的厚度是2mm;激光为波长488nm的氩离子激光(光功率约50mw)。我们测量了透射光和反射光的光强随时间的变化规律。本文研究的主要内容有:通过调整衰减片改变入射光功率,测量不同功率的光入射时透射光光强随时间的变化曲线;改变入射角度,测量光从不同角度入射时透射光光强随时间的变化曲线;改用其它激光器重复上述实验。通过实验,我们发现这一现象和入射光的功率有关,波动的周期随着功率的减小而变大,或者说,功率越小实验现象越不明显;入射光线的入射角越大实验现象就越不明显;反射光的现象与透射光有互补的趋势;光从基底入射与从膜面入射的实验现象在特征上一致。此外在实验中,我们发现用氩离子激光调制功率较弱的氦氖激光时的非线性现象。当氩离子激光与氦氖激光辐照到金膜上的同一位置时,氦氖激光的透射光光强增加了近一倍。在通过对实验现象的综合分析之后给出了定性的物理解释。更多还原

【Abstract】 We have investigated a new phenomenon in this paper. The intensity oftransmission and reflection will change with time when a laser beam input on anAu-film. In the experiment, the thickness of Au-film and glass-substrate are 50-60 nm and 2 mm respectively. Wavelength of the Ar+ laser is 488 nm . Wemeasured intensity of transmission and reflection and find that they have anobvious variation with time.The main works included the transmission intensity were measured whenintensity of incident laser was changed and incident angle was changed. Throughanalysis of experimental results, we find the intensity of transmission andreflection has the relation with the intensity of incident laser. The period oftransmission intensity wave is increase as the intensity of laser descends.Meanwhile, the intensity change of transmission intensity wave becomes weakwith lowering power. On the other hand, the phenomenon of nonlinear wave isdisappear when we decrease the incident angle. There is same result when thelight input on Au-film or glass-substrate. Finally we found that the transmissionintensity of He-Ne laser will increased when the Ar+laser input on the same point.更多还原