Abstract

A holographic 3-D disk employing the shift multiplexing method has been presented in the reference [1]. The technology makes it possible to provide a 3-D holographic data storage system with existing 2-D disk technologies such as the focusing and tracking servo methods. However, the system requires two separate optical paths for spherical reference beam and planar object beam in order to create holograms on the media. In reference [2], another holographic disk recording/read-out method is proposed. In this method, a laser beam is focused inside a photosensitive layer with a reflecting unit underneath to generate a standing wave, by which an index grating is produced. This method, however, entails a problem: the reference light interferes with the reconstructed light on the image capture device. In this paper, we present a new recording/read-out method which solves the problems in the two methods mentioned above. The construction of the optical head, the structure of the media employing the new method and its experimental results will be presented.

© 1998 Optical Society of America