Optical data storage using a solid immersion lens

We review the progress toward achieving high density and high data rate optical recording using a recently developed near-field optical technique based on the Solid Immersion Lens (SIL). The SIL is a truncated glass sphere which serves to increase the numerical aperture of the optical system by n2, where n is the index of refraction of the lens material. Using 780 nm light, a 317 nm focused spot size has been achieved by placing the SIL in contact with a sample. By mounting the SIL on a magnetic storage type slider, we have flown the SIL on a magneto-optical disk and demonstrated the writing and reading of data bits at frequencies in excess of 1 MHz. We project that using this technique it will be possible to write and read 300 nm domains at high data rates without utilizing shorter wavelength lasers.