Patent Number: 8,497,052

Title: Method for determining recording exposure for holographic recording medium and method for recording thereon

Abstract: An optimal recording exposure is determined by varying in the first to nth stages the recording exposure with a write laser beam to record a bright pattern image and a dark pattern image in each stage as the first to nth bright pattern images and the first to nth dark pattern images, respectively; irradiating the respective pattern images with a read beam to detect the intensity of a diffracted beam from the central portion of each image of the bright and dark patterns; calculating Sa.sub.1/Sb.sub.1=SNR.sub.1, . . . , and Sa.sub.n/Sb.sub.n=SNR.sub.n, where Sa.sub.1 to Sa.sub.n are the intensity of a diffracted beam from the first to nth bright pattern images and Sb.sub.1 to Sb.sub.n, are the intensity of s diffracted beam from the first to nth dark pattern images; and determining a recording exposure which is given at the SNR.sub.max being the maximum value of the resulting SNR.sub.1 to SNR.sub.n.

Inventors: Yoshinari; Jiro (Tokyo, JP), Hayashida; Naoki (Tokyo, JP), Fujii; Shohei (Tokyo, JP), Tanaka; Kazushi (Tokyo, JP)

Assignee: TDK Corporation

International Classification: G03H 1/00 (20060101); G03H 1/26 (20060101)

Expiration Date: 2021-07-30 0:00:00