Holographic recording apparatus, holographic reproducing apparatus and holographic recording and reproducing apparatus

摘要

A holographic recording apparatus causes reference light and information light to interfere with each other, and records the interference pattern in a recording medium. The holographic recording apparatus has an objective lens and a focus position controller. The objective lens focuses both the reference light and the information light at a focus position of the recording medium. The focus position controller changes the focus position into a predetermined position on the light path of the reference light.