| 摘要 |
PURPOSE:To vary equivalent refractive indice Ne, i.e., propagation constants, of respective waveguides and make the waveguide with a larger equivalent refractive index have a smaller propagation loss alpha and obtain a high output light beam by a method wherein a distance between a layer which functions as an absorbing and reflecting element for a guided light and an active layer is gradually varied every one of parallel stripes. CONSTITUTION:A quintuplex-stripe part 14 is an inclined active layer which is formed with an inclination against a current blocking layer 2 so as to make a distance between the active region and the absorbing region (current blocking layer) varied every waveguide. By this injection of a current, the parts of the active layer above the stripe shape trenches 8 are turned into active regions and five elements make oscillation while being coupled with each other. As the larger the distance between the inclined active layer 14 and the current blocking layer 2, the smaller the influence of absorption and reflection of the layer 2 in the region where a P-type AlGaAs lower cladding layer 3 is relatively thin, an equivalent refractive index Ne is large and a propagation loss alpha is small. By the effect that light converges into the part where an equivalent refractive index Ne is large, the shape of the light distribution of a basic array mode is biased to the left and the propagation loss alpha becomes smaller toward the left side. In other words, the mode gain to the basic array mode becomes larger than the mode gain to a higher degree mode so that the lateral mode of the integrated laser can be controlled to be the basic mode. |
