Read-only optical disk with superresolution

Publisher Website
Google Scholar
Abstract
The possibility of achieving superresolution in a read-only optical disk system with modified disk structures was investigated by simulation. The disk differs from the existing disks (such as compact disk) in addition of bilayer semiconductor materials. The absorption coefficient (α) of the semiconductor materials near band edge can be approximated by α∝(hν−EG)1/2 with hν as the photon energy and EG the band gap. Since the band gap EG within a certain range above room temperature decreases almost linearly with increasing the temperature, a strong nonlinearity of transmittance can be obtained by choosing a proper combination of EG and wavelength of the readout light source. Simulation results reveal that the spacial cutoff frequency can be significantly increased by the nonlinear transmittance of the additional semiconductor layers near the band edge.