Optical disk data storage system with improved solid immersion lens

摘要

An optical disk drive uses an air-bearing slider that supports a solid immersion lens (SIL) with a patterned thin film formed at the focus of the SIL to act as a secondary radiation source. The thin film is patterned to define either an "aperture" or a "scatterer", both of which localize the interaction of the disk drive's incident light beam with the underlying optical disk to create an effectively smaller light spot. In one embodiment the patterned thin film is opaque with a small aperture having a diameter less than the wavelength of the incident light beam. The aperture localizes the transmission of the incident light beam to the area of the aperture and generates an evanescent field that interacts with the optical disk. In a second embodiment, the patterned thin film is metallic and formed as dot that serves as a scatterer. The scatterer acts as an antenna or secondary light source to locally reradiate a portion of the incident light beam to the optical disk. Both approaches result in disk drive that has a smaller effective light spot than would be obtained if the SIL were used alone, provided that the optical disk is placed within sub-wavelength proximity of the aperture or scatterer.