Semiconductor laser device and optical disk apparatus using the same

摘要

A semiconductor laser device of the present invention includes a substrate 201 made of n-type GaAs, an active layer 204, and a pair of cladding layers sandwiching the active layer 204. The device further includes a spacer layer 205 adjacent to the active layer 204 and a highly doped saturable absorbing layer 206. The carrier life time is shortened by doping the saturable absorbing layer 206 in a high concentration, whereby stable self-sustained pulsation can be obtained. As a result, a semiconductor laser device can be obtained, which has a low relative noise intensity in a wide range of temperatures.