Patent attributes
A semiconductor laser device includes a semiconductor laser portion, a window layer structure portion, a first inter-element portion, and a pre-placed optical element portion on an InP substrate. The semiconductor laser portion includes an InGaAsP layer and an InP layer located on the InGaAsP layer. The window layer structure portion of a double heterojunction structure has the same optical axis direction as the semiconductor laser portion and is located apart from the semiconductor laser portion. The first inter-element portion has a 100-μm or less thickness in an optical axis direction, is in contact with an end face on a side of the window layer structure portion adjacent to the semiconductor laser portion and includes an InGaAsP layer and an InP layer of the same layer configuration as the semiconductor laser portion. The pre-placed optical element portion of the double heterojunction structure has a first end face in contact with the first inter-element portion and a second end face mutually opposed to the first end face and in contact with one end face of the semiconductor laser portion.
