| 摘要 |
PURPOSE:To simplify the constitution of the whole optical system and to reproduce a stable signal by using an optical circulator. CONSTITUTION:A laser beam radiated from a semiconductor laser SL3 is deflected in three directions by an expansion lens 10 and an acoustic-optical polarizer 11, made incident upon the port PA of the optical circulator CLT12 through a lens L11 and radiated to an magneto-optical disk 4 through a port PB as linearly polarized light. The reflected light from the disk 4 is made incident upon the CLT12 and projected from a port PC. The three projected beams are divided by a half mirror H3 and received by photodiode arrays D4, D5 respectively through analyzers A3, A4 and a cylindrical lens L13 and an information signal IS2, a focus error signal FE3 and a tracking error signal TEST2 are outputted. |
