| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor laser which emits a laser beam and a lifting-type optical pickup device which records and reproduces information by using the semiconductor laser as a light source. SOLUTION: An aperture 10 is provided on the emission end of a semiconductor laser 4', in order to realize high density record/reproduction by light spot contraction. The aperture 10 has a hole which is drilled so as to have a diameter smaller than the cross-section width of the active region of the semiconductor laser 4', and a laser beam is restrictively emitted through the hole to contract a light spot on an optical disc 1. With this constitution, practically high density record/reproduction which is useful for a miniturized information processor can be realized. |
