In a high power semiconductor laser device, first and second conductivity type clad layers are provided. An active layer is interposed between the first and second conductivity type clad layers. A first optical guide layer is disposed between the first conductivity type clad layer and the active layer. A second optical guide layer is disposed between the second conductivity clad layer and the active layer. Also, an intentionally undoes optical loss confinement region is formed in a portion of at least one of the first and second conductivity type clad layers overlapping laser beam distribution.