HOLOGRAM RECORDING DEVICE, HOLOGRAM REPRODUCTION DEVICE, HOLOGRAM RECORDING METHOD, HOLOGRAM REPRODUCTION METHOD, AND HOLOGRAM RECORDING MEDIUM

摘要

There is provided a hologram recording device capable of easily performing multiplex recording and reproduction to/from a hologram recording medium. The hologram recording device includes: an optical system for focusing a signal light modulated by an optical modulation element and a reference light phase-modulated by a phase modulation element substantially to the same place; and a distance control mechanism for controlling the distance between the phase modulation element and the hologram recording medium. By controlling the distance between the phase modulation element and the hologram recording medium, it is possible to perform multiplex recording to the hologram recording medium. In an ordinary phase-correlation multiplex method, multiplex recording is performed by shifting the focusing position in the surface direction of the hologram recording medium. As compared to this, the present invention can perform multiplex recording without requiring shift in the surface direction. By performing shift in the surface direction of the hologram recording medium, it is possible to further increase the recording capacity. In this case, the shift amount can have a margin as compared to the ordinary phase-correlation multiplex. ® KIPO & WIPO 2007