Robust detection of deeply subwavelength pits in simulated optical data-storage disks using photonic jets

We report a means to detect deeply subwavelength pits in optical data-storage media by employing the recently observed giant backscattering perturbation phenomenon of the photonic jet. We conducted microwave experiments with dimensionally scaled-up pits and lands in a simulated optical data-storage device. These measurements were backed up by three-dimensional finite-difference time-domain computational solutions of Maxwell's equations. Results indicate that pits having a lateral area of 0.025 square wavelengths, i.e., much smaller than current BluRay™ device features, can be robustly detected with a contrast ratio approximately 28dB greater than that provided by a lens system.