A high-NA solid immersion objective for imaging a Blue-ray disc and investigating subsurface damage

摘要

Nano-scale resolution in miniature optical systems has been realized in the optical data storage industry. Numerical apertures greater than unity have been achieved in by utilizing the high index material of a hemispherical Solid Immersion Lens (SIL), which increases the resolution of the backing objective by a factor that is related to the refractive index of the SIL. In this research, a custom Hyper-Blu-Disc (HBD) NA=1.4 SIL objective is utilized for high-fidelity readout of data pits beneath a 100μm thick cover layer on an optical Blu-Ray Disc. If realized commercially, the increase in data density could be 3X today's Blu-Ray technology. A distinct difference between this work and other work with SILs in optical data storage is the relatively thick cover layer of 100μm. Recently, there has been interest in discovering new ways to apply the technology and methods used in optical data storage for other means. The inherent design of the HBD objective to image through a shallow layer of dielectric material may lend itself to be used as an effective means for characterizing subsurface damage in optical materials. This research will furthermore investigate the HBD objective as a means of detecting subsurface damage.