The width of a current pass region of a semiconductor laser device is
narrowed as much as possible, thus implementing a stable single
transverse mode. The device is relatively resistant against physical
impact. The device includes a semiconductor substrate having first and
second opposite surfaces, and, in order, a first conductive type clad,
active layer, etch stop layer, current blocking layer formed in a
V-groove shape so that a part of the etch stop layer is exposed, second
conductive type clad formed entirely over the entire of the V-groove and
the current blocking layer, optical guide layer, current pass
facilitation layer, cap layer, second conductive type electrode, and a
first conductive type electrode formed on the second surface of the
semiconductor substrate.