Consideration and control of writing conditions with a near-field APSIL probe

The Solid Immersion Lenses (SIL) and aperture probes are two near field optical techniques that are capable of generating smaller spot size than that of far-field optical systems. Neither technique can generate both ultra-small spot size and exhibit high optical efficiency. Small spot size produces higher contrast signals, which leads to an increase in signal-to-noise ratio (SNR) and an enlargement in the capacity of an optical disk. Higher optical efficiency gives higher throughput in the optical system, which accelerates data rate. The technique of near-field Aperture SIL (APSIL), which combines a dielectric aperture probe and a SIL, is a promising method to achieve both small spot size and high optical efficiency. The objective of this paper is to explore the writing conditions for implementing APSIL to reduce mark size to a fraction of that from the far-field data storage systems. In this paper, we investigate the effect of polarization of the light on the spot profile and the optimal axial focus position by experiments and simulations.