【摘要】 本文研究了可擦除磁光记录读出光学系统,分析了激光二极管整型系统,建立了扩束棱镜优化设计条件,推导出了最优偏振分光镜的物理模型。更多还原

【Abstract】 A novel optical system used in a magneto-optical recording/reproducing device is described. The system is of a single optical path with a single laser diode. The operations of writing, erasing or reading can be performed by changing the power of the laser diode and the direction of an applied magnetic field. During operation, the beam shaping system, the polarized property of the optical element and the optical feedback from disc to laser diode will all affect the accuracy of information writing /erasing and the carrier-to-noise ratio (C/N) of information reading. The optimal design of the optical beam shaping system to improve the performance and the polarized coefficients of optical element are discussed at some length. The laser diode is equivalent to a rectangular wave-guide resonant cavity. The laser beam from the diode must be shaped to give an ideal beam spot on the magnetic recording medium. An "up-and-down" couple of achromatic prisms or a couple of cylindrical lenses are used for the beam extending system. To obtain a satisfactory beam focus spot, it would be best if the beam extending ratio is designed to be changeable.The characteristic of light intensity and the variation of polarized states in the optical system are analyzed with Jonse transition matrix. The polarized factors are optimized. The reading of C/N, the optical feedback to laser diode and the accuracy of tracking and focusing are all closely related to the oltimized factors of the optical system.更多还原