OPTICAL INFORMATION STORAGE DEVICE AND OPTICAL DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a compact optical information storage device which reduces noise due to wobbling and the like and which enables high density recording. SOLUTION: The optical device 410 is provided with a reflection surface 64 consisting of the main part that reflects, in a prescribed direction, a signal light reflected from a separation surface 61 and a mask part 411 that has optical characteristics different from those of the main part.