INFORMATION RECORDING MEDIUM AND METHOD FOR PRODUCING THE SAME, RECORDING OR REPRODUCING METHOD, AND OPTICAL INFORMATION RECORDING AND REPRODUCING DEVICE

摘要

An information recording medium is provided that includes a recording portion (3), which is irradiated with a recording light or a reproducing light so that information is recorded or reproduced thereto or therefrom. The recording portion (3) contains a first phosphor and a photon-mode photosensitive material. The first phosphor has a property of absorbing a first light having a wavelength of λ1/n and then emitting a second light having a wavelength longer than that of the first light, where λ1 is a wavelength of the recording light. The photosensitive material absorbs the second light and then exhibits a change in an optical constant thereof. A n-photon absorption sensitivity of the first phosphor with respect to the recording light is greater than a n-photon absorption sensitivity of the photosensitive material with respect to the recording light, where n is an integer not less than 2.