气泡的远场干涉分析及应用

提出了一种分析气泡远场干涉的理论模型。平行激光束照射到透明介质中的气泡上,折射光束与全反射光束在远场发生干涉形成内密外疏圆环状干涉条纹,推求了两平行出射光线的光程差公式和两光线之间的距离公式,分析了圆环状干涉条纹内密外疏的原因,给出了计算干涉条纹存在区域和最高干涉级的方法。通过干涉方法可以测量气泡的直径,能够用于介质深处气泡尺寸的测量。利用远场干涉对玻璃水箱、平板玻璃、玻璃棱镜中的气泡直径进行了测量,其中玻璃棱镜中气泡直径测量结果与用阿贝比长仪测量结果对比,相对差为0.9%。预期了气泡远场干涉在运动气泡尺寸、泡内气体折射率、透明光疏介质中光密介质球尺寸测量等方面的应用。

Far-Field Interferometric Analysis and Application of Bubble

A theoretical model of analysis of bubble farfield interference is given,when parallel laser beam is irradiating the bubble in a transparent medium,the interference between refraction beam and total reflection beam comes into being and the thick-inside-and-thin-outside interference rings have taken shape in far field,a formula on optical path length difference and a formula on distance of two parallel exit rays are derived,reasons for thick-inside-and-thin-outside interference rings are analyzed,the method of calculating interference regions and the largest constructive interference ordinal number are given.The diameter of bubble can be measured by method of interference,the size of bubble can be measured in the depths of medium.The diameters of bubbles in the glass water box,plate glass and glass prism have been measured by method of far-field interference,and the measured result of diameter in glass prism by the interference is compared with that by the Abbe comparator,the relative difference of which is 0.9%.The application of measurement in the size of moving bubble,refractive index of gas in bubble,size of optically denser medium ball in a transparent optically thinner medium is expected by method of far-field interference.