Near Field Recording on First-Surface Write-Once Media with a NA=1.9 Solid Immersion Lens

Abstract

We present a single-wavelength near field recording set-up with a blue laser and a NA=1.9 solid immersion lens in a conventional focus and tracking actuator. The most important aspects to realize such a near field recording system are discussed, in particular, gap error signal normalization and correction of chromatic aberration of the objective lens. First recording results demonstrate that the set-up is fully operational.

Self-Cleaning Effect of Solid Immersion Lens Using Photocatalyst TiO2 Film for Near-Field Recording

“…For next generation high-density optical memory, solid immersion lens (SIL) based near-field recording (NFR) technology has received a lot of attention recently. [1][2][3][4] However, there are still some remaining technical barriers to be solved before its practical application. One difficulty originates from contamination on the SIL and the disk surface since SIL-based NFR is based on a narrow gap of around 25 nm between the SIL and the disk.…”

High-Density Near-Field Recording on Cover-Layer Protected Discs Using an Actuated 1.45 Numerical Aperture Solid Immersion Lens in a Robust and Practical System

“…As described in ref. 12, this requires normalization of the gap error signal to the incident laser power, e.g., by using a forward sense detector. A telescope configuration in front of the lens is used to manually adjust the focus position inside the disc.…”

A study of near field recording optics for cover-layer incident dual-layer disc with an NA=1.45 hemispherical solid immersion lens

“…In the past few years, there have been many studies on near field recording (NFR), such as by Ishimoto et al [1] and Verschuren et al [2] Verschuren et al proposed a cover-layer incident dual-layer (DL)-disc with a hemispherical solid immersion lens (SIL) and presented an improved design of a hemispherical SIL and bi-aspherical lens that is able to focus free from wavefront aberration through a 3µm cover-layer [3]. The first section describes the practical design of the cover-layer incident DL-disc with a hemispherical SIL without change in distance between the first lens and the SIL based on the previous report.…”