We have proposed a new confocal readout system which is based on the combination of two N-zone circular phase-only transverse superresolving pupils to improve transverse superresolution. The procedure for designing such an improved system is presented. Results of comparisons between the performance of the proposed system and the transverse superresolving pupils indicate that with the same Strehl ratio the former has much higher transverse superresolution capacity and significantly lower sidelobe intensity.
"New approach for improving transverse superresolution in optical data storage," Optical Engineering 44(12), 125202 (1 December 2005). https://doi.org/10.1117/1.2139667