SEMICONDUCTOR DEVICE WITH SEMICONDUCTOR LASER AND OPTICAL AMPLIFIER INTEGRATED THEREON

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device in which a semiconductor laser and an optical amplifier are integrated with can be used as an excitation light source for a fiber amplifier. SOLUTION: A semiconductor device in which a semiconductor laser and an optical amplifier are integrated is provided with a semiconductor laser having a first optical waveguide 16 formed on a semiconductor substrate, optical amplifier having a second optical waveguide 17 formed on the substrate so that light from the semiconductor laser can be combined, and electric means for independently exciting the semiconductor laser and the light amplifier. In this case, the second optical waveguide 17 is connected with the first optical waveguide 16 with the same width and the width is increased according as it goes toward the edge face. An active layer 22 of the optical amplifier is connected with the first optical waveguide 16 with the same width, and this active layer 22 is provided with an area having the same width as the second optical waveguide 17, and an area connected with the area whose width is decreased according as it goes toward the edge face.