Near-Field Recording with a Solid Immersion Lens on Polymer Cover-layer Protected Discs

Abstract

Recent demonstrations have shown that near-field optical recording with a solid immersion lens in a conventional actuator is a strong candidate for optical storage beyond Blu-ray Disc. All results published so far were obtained with so-called first-surface configurations, in which the data layer is not protected by a cover-layer. In this paper we demonstrate a next step towards creating a system suitable for a commercial product with removable discs. First results are presented for read-out of discs with a few µm protective polymer cover-layer and a solid immersion lens with NA=1.45 and λ=405 nm.

An RLL code design that maximises channel utilisation

“…This is a quick look at the applications in a relatively new technology area: Blue-ray storage systems. By using a Solid Immersion Lens (SIL) that flies over the disc, near-field optical recording achieves high-numerical aperture (NA) (Verschuren et al, 2006). The distance between the lens and the disc is just few tens of nanometres.…”

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

“…More details can be found in ref. 7. To compensate chromatic aberration during recording due to a shift of the laser wavelength, an injection moulded correction plate with a non-periodic phase structure (NPS) is used.…”

“…In previous papers, 6,7) we proposed and presented first results for a near-field system using media with a protective cover-layer of a few micrometers in thickness. One major advantage of this approach is the superior data protection and robustness compared to a so-called first-surface configuration.…”

“…Over the past few years, we have shown that near-field recording (NFR) using an actuated solid immersion lens (SIL) has great potential for an evolutionary continuation of the optical storage roadmap. [1][2][3] Using a blue-violet laser with ¼ 405 nm in combination with a very high numerical aperture (NA) SIL-based lens [see Fig. 1(a)], the spot size can be further reduced than is possible with conventional, far-field optics.…”

Contrast enhancement of microsphere-assisted super-resolution imaging in dark-field microscopy

“…ecause of the so-called diffraction limit, the imaging resolution of conventional optical microscopy is limited to around half of the illuminating wavelength λ. To date, several techniques have been realized to break the diffraction limit, including solid immersion lenses, 1,2) nearfield scanning probes, [3][4][5] fluorescence microscopy, 6,7) and negative index materials. 8) Nonetheless, the applications of these methods have been hindered to some extent because of their sophisticated engineering designs or various technical limitations.…”