OPTICAL PICKUP DEVICE AND OPTICAL REPRODUCTION DEVICE

PROBLEM TO BE SOLVED: To provide an optical pickup device and an optical reproduction device which can smoothly and successfully reproduce a recording medium by effectively suppressing a bad effect of stray light even when having many recording layers in a lamination direction. SOLUTION: The optical pickup device includes: an SIL 21 which emits reproduction light; a beam splitter 22 which leads the reproduction light to a recording layer 15 and a mirror 23 in the recording medium 10; an optical detector 24 which receives the reproduction light (signal light) reflected by the recording layer 15; the mirror 23 which superimposes the reproduction light (reference light) on the signal light; an optical path adjustment section which changes optical path length of the reference light according to the reference light. Displacement of the mirror 23 changes the optical path length L1 and when the difference of the optical path length L1 and optical path length L2 becomes within the range of coherence distance Δlc, the signal light and the reference light interfere and output of the optical detector 24 increases in the shape of a pulse. The output become higher than the signal component of the stray light by several steps. COPYRIGHT: (C)2009,JPO&INPIT