| 摘要 |
PURPOSE:To improve the capalitity of a laser element as a light source for light fiber by making an active region area of the under surface of a semiconductor layer 1 thicker than the remaining areas, thereby permitting discontinuous changes in effective refractive indexes of laser light along a direction in which the laser light proceeds and a direction vertical thereto. CONSTITUTION:A first semiconductor layer 1 including an active region is sandwitched between a second semiconductor layer 2 and a third semiconductor 3, each having a relatively small refractive index and a wide forbidden gap in comparison with the semiconductor layer 1. By making an active region area W on the under surface of the semiconductor layer 1 thicker than the remaining areas, its effective refractive indexes to laser light along the direction in which the laser light proceeds and the direction vertical thereto are discontinuously changed. Thus it can be effectively used as a light source for light fiber communication. |
