Magnetooptic head

Abstract

Abstract PURPOSE:To increase both Kerr effect and S/N and to decrease the number of component parts, by providing the functions of beam formation and beam splitter to a prism which is put into the optical path of a photomagnetic recorder/ reproducer and applying a multilayer coat to the prism. CONSTITUTION:Laser light is radiated from a light source 1 and thermomagnetically recorded to a photomagnetic disk 7 via a condenser lens 2, polarizer 3, forming prism 13 and lens 6. In a reading mode, the reflected light having a rotated polarizing face which is obtained with Kerr effect produced by irradiating the laser light of the light source 1 to a photomagnetic disk 7 like the recording mode is transmitted to the lens 6, the prism 13, a lens 10 and a photodetector 11. Thus the signals are detected by an optical detector 12. The prism 13 converts an oval beam into a circular beam and at the same time increases the Kerr rotary angle with a dielectric multilayer coat applied to the slope of the prism. The receiving face of the detector 12 is divided into 4 regions, and the receiving light volume is calculated for each of the divided regions to control a servo system (not shown in figure). As a result, the number of component parts is decreased and the S/N is improved.

Inventors

• 👤 Toshihisa Deguchi
• 👤 出口　敏久
• 👤 Kenji Oota
• 👤 賢司 太田
• 👤 Akira Takahashi
• 👤 明 高橋
• 👤 Hideyoshi Yamaoka
• 👤 山岡　秀嘉

Bibliographic Details