High optical efficient integrated head for use in magneto-optical disk drive

We developed an integrated optical head for use with MO (magneto-optical) disks that makes it possible to adjust the focusing error signal (FES) and tracking error signal independently and to obtain high gain servo signals with a DOE (diffractive optical element). It prevents the changing of the FES caused by temperature changes by using a quasi-phase conjugate system. The cylindrical beam-splitter and the automatic power control-DOE achieve high optical efficiency and MO signal quality.