| 摘要 |
PURPOSE:To realize a measurement of the multiple refractive index without measuring the diameter of the filament previously, by irradiating the laser beams the polarized faces of which are parallel and vertical to the filament and then observing the shift of the interference fringes. CONSTITUTION:The shift dtheta is observed between the interference fringes which are caused when the laser beam the polarized face of which is parallel to the filament 2 satisfying the conditions of DELTAn<lambda/D to the filament 2 and the interference fringes caused by irradiating the laser beam the polarized face of which is vertical to the filament 2. Thus the double refractive index DELTAn is obtained based on the fixed equation. In the above equation, lambda shows the wavelength of the beam source with D showing the diameter of the filament 2 respectively. The above-mentioned equation used e.g. DELTAn=(dtheta/2)[1+[n/(n-1)]sin(theta/2)] or DELTAn=dtheta/2, where theta shows the position of the interference fringes and n shows the refractive index of the filament 2 each. |
