Pupil plane characteristics and filtering for optical data storage using circular polarization with a solid immersion lens

Solid immersion lens (SIL) system is an excellent candidate for future technology to increase the data density of optical data storage. In a SIL system, properties of reflected light seen at the exit pupil strictly depend on the air gap thickness between the SIL and the top surface of the medium. Moreover, signal level and contrast reflected from the data bit is directly related to the modulation of δn=n₀. In this case, the signal contrast can be improved by using an appropriate filter. However, unlike the incident beam of a linear polarized light, circular polarized light requires deeper understanding of the pupil plane characteristics corresponding to the vectorial nature of light.