Patent ID: 8649408

Claim:
A semiconductor laser device comprising: an active layer; a p-type semiconductor layer on the active layer; a pair of grooves formed by etching into the p-type semiconductor layer; a stripe sandwiched by the pair of grooves and having a shape of a ridge; a pair of buried layers made of insulator to bury the grooves; a protective layer made of insulator formed on the buried layers, the protective layer including an opening, the opening is wider than the width of the ridge; and an electrode filling the opening, the electrode contacts with an entire part of a top surface of the stripe, the electrode contacts with top surfaces of the buried layers, wherein bottom surfaces of the grooves at sides farther from the stripe have a shallower extent than bottom surfaces at sides closer to the stripe, wherein each bottom surface of the grooves includes a deepest portion that is a portion farthest vertically from the top surface of the stripe, and the deepest portion is closer to the stripe than from an edge of the grooves that is farthest from the stripe.