Holographic information recording and reproducing apparatus

Abstract

In a light information recording apparatus, a hologram pattern diffracts a reference light such that the reference light which is emitted from an objective lens to a recording medium side, is superimposed on a information light which is emitted from the objective lens to the recording medium side in the vicinity of a light condensing point of the information light, and the reference light is condensed at a different point from the light condensing point of the information light. In a light information reproducing apparatus, the hologram pattern diffracts the reference light in a going path such that the reference light which is emitted from the objective lens in a returning path comes off a light path of the reference light in the going path.

Description

technical field [0001] The present invention relates to an optical information recording device and an optical information reproducing device, and more particularly, the present invention relates to an optical information recording holographic information in a recording medium by using interference fringes obtained by interference of information light and reference light A recording device and an optical information reproducing device for performing information reproduction on a recording medium by diffracting reference light using interference fringes. Information is holographically recorded in the medium by means of interference fringes. Background technique [0002] In an optical information recording apparatus that performs holographic information recording in a recording medium, it is necessary to superimpose reference light and information light in the recording medium to generate interference fringes. For this purpose, information light and reference light must be ob...

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Problems solved by technology

[0003] However, with the structures proposed in JP-A-2006-039181, WO2004 / 102542, and JP-A-2005-292765, it is difficult to generate a light beam with uniform light intensity, resulting in a problem of light quantity loss

In addition, when recording is performed, it is impossible to obtain excellent recording characteristics because the contrast of interference fringes is low; and when reproduction is performed, it is impossible to obtain a signal of good quality because stray light often occurs and light is incident on a light receiving member.

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