Method for Recording and Reproducing a Hologram and Apparatus Therefor

摘要

A hologram recording method is a method of recording a hologram, on a hologram recording apparatus that records information by forming a diffraction grating through oppositely irradiating the signal beam and the reference beam to the hologram record carrier. The hologram recording method includes a step of focusing the reference beam at a first numerical aperture from a first effective diameter by means of the reference-beam objective lens, a step of separating the reference beam in a part on the optical axis and a neighborhood thereof to thereby produce from the reference beam a recording reference beam to passes through the hologram record carrier at a second numerical aperture smaller than the first numerical aperture from a second effective diameter smaller than the first effective diameter by means of the reference-beam objective lens of the reference-beam optical system, and allowing the recording reference beam to exit coaxially to the reference beam, and a step of not allowing only the recording reference beam to exit toward the hologram record carrier by means of the signal-beam optical system.