| 摘要 |
PURPOSE:To record, reproduce, and erase information with a singular light source by changing the direction of the magnetic field impressed to a Faraday rotor. CONSTITUTION:A laser beam emitted from a common laser beam source 21 for recording is turned into a parallel beam by a focusing lens 22, and injected to a Faraday rotating means 23. The Faraday rotating means 23 consists of a magnetic pole 41 consisting of a semirigid magnet equipped with an exciting coil 42 for impressing a magnetic field and a Faraday rotor 43 consisting of a YIG (Y3Fe5O12) crystal added with Bi, and has the function to turn the plane of polarization of the luminous flux injected to the Faraday rotor 43 to an angle of + or -45 deg. by passing a pulse current through the exciting coil 42. The parallel beam injected to the Faraday rotating means 23 is transmitted wherein the pulse current is not passed, and then recorded on the bit recording surface of an optical disk 35. |
