Patent attributes
The present invention provides a semiconductor optical element applicable to an EC-LD or an SLD, and an external cavity laser having the semiconductor optical element. The semiconductor optical element has a pair of cleavage surfaces, and comprises a semiconductor substrate 11 having a base surface and a planer structure provided on the base surface and provided with a waveguide 1G having an active layer. The waveguide 1G has an end surface with low reflectivity and another end surface with certain reflectivity. The waveguide 1G includes an end portion having a first optical axis in the vicinity of the first end surface 1TL and an end portion having a second optical axis in the vicinity of the second end surface 1TH, the first optical axis being inclined at a first angle ΦL other than zero degree with respect to a normal to the first end surface 1TL, the second optical axis being inclined at a second angle ΦH other than zero degree with respect to a normal to the second end surface 1TH, the first angle ΦL being different from the second angle ΦH. The end portion of the waveguide 1G is different in width from the other end portion of the waveguide 1G.
