| 摘要 |
PURPOSE:To rotate the plane of polarization of a light beam uniformly by arranging a magnetooptic material and an electromagnet, providing a total reflection surface in the magnetooptic material, and making the incidence/projection direction of a light beam different from the magnetic field direction of the electromagnet. CONSTITUTION:A semirigid magnetic body 21 and a coil 22 constitute the electromagnet and magnetooptic crystal 23 is arranged in the gap of the electromagnet. End surfaces of the magnetic body 21 and crystal 23 are both cut at 45 deg.. When a current is flowed to the coil 22, the end surface of the magnetic body 21 is magnetized into an N or S pole. The crystal 23 has larger magnetic permeability than air and almost all of lines of magnetic force permeate the crystal 23. A light beam incident at right angles to a magnetic field is reflected totally by the 45 deg.-cut end surface of the crystal 23 at right angles to travel along an optical path 24, and reflected totally at the other end of the crystal 23 similarly to exit from the crystal. When the light beam travels along the optical path 24, Faraday effect is caused by the magnetic field applied to the crystal 23 and proper optical path length is selected to rotate the plane of polarization by + or -45 deg.. Thus, the rotation of the plane of polarization is made uniform and the power consumption is reduced. |
