Performance analysis of a multimode waveguide-based optical disk readout system

We propose a method to improve the optical resolution to read out optical disks, without making the spot size on the disk smaller than the diffraction limit. The idea is to reconstruct the bit pattern from the complete field profile (including amplitude and phase) of the light reflected from the disk. We measure the phase and amplitude information by picking up the wave front into different modes of a bimodal waveguide. Once picked up, these modes can be split by a photonic integrated circuit to be measured by separate detectors. By combining the information from the responses from the different modes, we can improve the bit error rate substantially.