SURPASS · SUper-Resolution Photonics for Advanced Storage Systems

The purpose of the restructured SURPASS project is to develop key technologies to achieve super-resolution beyond the diffraction limit in air at visible wavelength. The application fields covered by the project are optical data storage, wafer inspection, maskless optical lithography and confocal microscopy.The first super-resolution technology is based on so-called super-RENS materials (Super-Resolution Enhanced Near-Field Systems). These materials, such as the semiconductor InSb, undergo a local modification of their refractive index properties above a certain power threshold of a focused laser spot. As a consequence they produce a reduction of the effective size of the laser spot. Super-RENS materials are developed mainly for optical ROM discs to allow the readout of recorded marks smaller than the resolution limit of the optical readout system. The maximum capacity of single-level Super-RENS discs will be studied theoretically and experimentally. In parallel, semi-transparent Super-RENS levels will be developed and the industrial potential of this technology for multi-level discs will be evaluated. The purpose is to propose a technological solution for the extension of the Blu-Ray format from 25 GB to 75-100 GB for high-definition video content distribution.The second super-resolution technology is based on micro-solid immersion lenses (µ-SILs) which enable to reduce a focused laser spot by a factor equal to the refractive index of the µ-SIL. A low-cost manufacturing process will be developed on 200 mm silicon wafers. The resolution of µ-SIL should be further enhanced by using engineered polarization, high index material, plasmonic nanostructures at focus or functionalization with a Super-RENS layer. The performances of high-resolution optical heads including a µ-SIL will be studied in various application fields such as wafer inspection, optical lithography and confocal microscopy.