To provide an optical information recording and reproducing device wherein a recording layer is prevented from decreasing in a storage capacity due to excessive irradiation of light thereto, and also an optical system for recording and reproduction is downsized and simplified.
The optical information recording and reproducing device of this invention records information on an optical information recording medium provided with an information recording layer on which the information is recorded by using holography. The optical information recording medium is formed on the information recording layer in the order of a protective layer and a reflecting layer, and the recording optical system of the optical information recording device focuses recording reference light on the reflecting layer of the optical information recording medium or in the vicinity thereof, and also focuses the information light before the boundary surface between the information recording layer of the optical information recording medium and the protective layer.
HORIGOME HIDEYOSHI
So Ishii
Juno Aoki