Holgraphic recording and reading method and holographic recording and reading apparatus

摘要

A method of holographically recording and reading information is disclosed. The method includes: recording information in a holographic recording medium by irradiating the holographic recording medium with a laser beam, wherein a transverse sectional area of the laser beam is divided into a central area for a signal beam and a ring-shaped area for a reference beam, the ring-shaped area surrounding the central area with a predetermined gap; and reading out the information from the holographic recording medium by irradiating the holographic recording medium with a ring-shaped readout beam having an area greater than that of the reference beam in at least one of directions inward of an inner diameter thereof and outward of an outer diameter thereof.