Patent attributes
The semiconductor laser device includes first and second light emitting portions each including a first cladding layer, an active layer and a second cladding layer, and each having a stripe structure. The stripe structure of the first light emitting portion has a section having a width changing along a resonator direction and includes a first front end face, and relationships of Wf1≧W1; W1>W2; and (Wf1−W1)/2L1<(W1−W2)/2L2 hold wherein Wf1 is a width on the first front end face; W1 is a width in a position away from the first front end face by a distance L1; and W2 is a width in a position away from said the front end face by a distance L1+L2 (whereas L1+L2≦L). The stripe structure of the second first light emitting portion has a section having a width changing along a resonator direction and includes a second front end face, and relationships of Wf2≧W3; W3>W4; and (Wf2−W3)/2L3<(W3−W4)/2L4 hold wherein Wf2 is a width on the second front end face; W1 is a width in a position away from the second front end face by a distance L3 (whereas L1≠L3); and W4 is a width in a position away from the second front end face by a distance L3+L4.