| 摘要 |
PURPOSE:To enable the secure laser oscillation of single longitudinal mode with small sized elements by a method wherein the laser oscillation of unnecessary mode is restricted by forming a short non-excitation part of the length approx. 0.1mm.. CONSTITUTION:When the width of a buried layer 108 of an excitation part under a stripe electrode 105 is W1, and that of a buried layer 109 of the non-excitation part W2, and the length thereof 0.1mm., the layers are formed to the relation of W1<W2. An electrode is not provided on an enlarged buried active layer 110. When a voltage is impressed by deciding the electrode 105 as the positive electrode and the electrode 106 as the negative electrode, a current flows in the layer 108 by the effect of the buried layer 111, and accordingly the buried active layer 101 becomes a photo amplification layer. The unnecessary Fabry- Perot resonation longitudinal mode, if sufficiently absorbed to the non-excitation part, is erased because of no reflection effectively from the end surface 113. |
