公开(公告)号：DE1286078B

公开(公告)日：1969-01-02

申请号：DEJ0031714

申请日：1966-09-06

Applicant: IBM DEUTSCHLAND

Inventor： MAX ,  ERHARD DIPL-PHYS DR ,  KULCKE ,  WERNER DIPL-PHYS DR ,  KURT KOSANKE

IPC: G02F1/31 ,  H04N3/08

公开(公告)号：DE1298218B

公开(公告)日：1969-06-26

申请号：DEJ0028448

申请日：1965-06-26

Applicant: IBM

Inventor： MAX ,  ERHARD DR ,  M KOSANKE KURT ,  FALLS WAPPINGERS ,  KULCKE ,  W DR WERNER

IPC: G02F1/09 ,  H01S3/105 ,  H01S3/10

Abstract: 1,053,086. Lasers. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 21, 1965 [June 29. 1964], No. 21755/65. Heading H1C. A laser has its optical cavity formed by mirrors 11, 12 of magnetic material one of which is partially transmitting, the mirrors being controllably magnetized so that the Kerr magneto optical effect causes an output ray circularly polarized in a selected direction to be obtained. The active medium may be dysprosium-doped calcium fluoride which radiates circularly polarized light when pumped and subjected to a magnetic field, or may be another medium the radiation of which is circularly polarized by quarter wave plates 14, 15. When the magnetic field applied to a mirror 11, 12 is in the same direction as the incident radiation, Fig. 1 (not shown), the reflected light becomes more strongly polarized in the right-hand sense. The converse applies when the direction of the magnetic field is reversed, Fig. 2 (not shown). The laser may be arranged so that the threshold for laser action is only exceeded if both mirrors produce circular polarization in the same sense. Then by reversing the magnetization of both mirrors the direction of circular polarization of the output light is reversed. Other relationships of magnetic directions in association with an optical cavity of higher Q can be used. In a modification one mirror is formed of a dielectric material having a constant reflectivity irrespective of the polarization direction. An output is then obtained which is circularly polarized in one direction or the other in accordance with the magnetization direction of the single mirror. By controlling the magnetization of the mirrors a modulated output may be obtained.