| 摘要 |
PURPOSE:To constitute an optical isolator even with a double refractive crystal, by arranging two sheets of double refractive crystal so as to eliminate the effect of the double refraction. CONSTITUTION:Linear polarized wave light is made incident to the axis (a) which is vertical to the axis (c) of a magnetooptic crystal having large thickness. Thus the output light is turned into an oval polarized wave due to the double refraction. In this case, a Faraday rotational angle theta equals to (180Ft/piB)sin(piB/ 180), where B=360(no-ne)t/lambda, F: Faraday rotational coefficient, lambda: wavelength of light, no: refractive index of normal light, ne: refractive index of abnormal light and B: phase delay angle due to the double refraction. Then the two crystals having the same thickness along the direction 6 of easy magnetization of the crystal are provided as shown in the figure so that the axes (c) of the crystals are orthogonal to each other. Thus the delay angle B equals to 360/lambda{(no- ne)t+(ne-no)t}=0, and theta=2Ft is obtained. This is identical with an equation of an isotropic magnetooptical material showing no double refraction. |
