Abstract: It is an object to provide filters for optical recording media capable of preventing diffuse reflection of informing and reference lights from reflective films of optical recording media and inhibiting noise therefrom without shifting the selective reflection wavelength even when the incident angle is variable, optical recording media of hologram type having the filters and capable of recording images with higher density over the prior art, methods for producing the optical recording media with higher efficiency and lower cost, and also optical recording methods and optical reproducing methods that utilize the optical recording media. In order to attain the object, provided are filters for optical recording medium, comprising a colorant-containing layer, wherein the colorant-containing layer comprises at least one of pigments and dyes, and a cholesteric liquid crystal layer is disposed on the colorant-containing layer, and also optical recording media of hologram type comprising the filter.

Abstract: The present invention provides a filter for optical recording media capable of preventing diffused reflection from a reflective layer caused by an information beam and a reference beam in the optical recording medium and preventing occurrences of noise without causing deviation in selective reflection wavelength even when an incidence angle is changed, a holographic optical recording medium that has not yet been conventionally provided, using the filter for optical recording media, a method for producing the optical recording medium efficiently at low-cost, and an optical recording and reproducing method using the optical recording medium using the optical recording medium. To this end, the present invention provides a filter for optical recording media containing two or more cholesteric liquid crystal layers laminated to one another, and a holographic optical recording medium using the filter for optical recording media.

Abstract: A novel optical plastic fiber comprising a core region and having a center line along a longitudinal axis of the fiber is disclosed. The refractive index of the core region increases along a direction going from a periphery portion to the center line in any plane perpendicular to the center line, and the birefringence index of the core region varies along a direction going from the center line to a periphery portion perpendicular to the center line in any plane parallel to the center line and containing the center line.

Abstract: A novel optical plastic fiber comprising a core region and having a center line along a longitudinal axis of the fiber is disclosed. The refractive index of the core region increases along a direction going from a periphery portion to the center line in any plane perpendicular to the center line, and the birefringence index of the core region varies along a direction going from the center line to a periphery portion perpendicular to the center line in any plane parallel to the center line and containing the center line.