The Development of a Novel Optical Floppy Disk Drive Using a Phase Change Optical Medium and a Quasi-Near-Field Optical Head

Abstract

The optical memory system still has some shortcomings such as slow tracking access speed and high fabrication cost due to its relatively heavy head weight and complex optical elements. To overcome these limitations, a new lensless optical floppy disk drive has been developed using a phase change optical floppy disk and an external cavity semiconductor laser with a good antireflection (AR) coating on the emitting facet. The main components of this novel system are a contact-type head of quasi-near-field optics and a phase change medium prepared on a flexible polyimide substrate. The AR-coated semiconductor laser oscillates externally with the disk and its laser emission output shows sufficient variance to detect the phase difference on the recording layer. In our primitive drive, the simple optical head shows good writing performance and the recorded marks present sub-micrometer size, which indicate the high possibility of the development of a new, inexpensive floppy system of above 500 MB data capacity.