| 摘要 |
PURPOSE:To enable low current operation at a room temperature by a method wherein the shape in a surface including an active layer of a mesa stripe is formed into one wherein the widths are different in the longitudinal direction of the mesa stripe. CONSTITUTION:The mesa stripe 20 which is sandwiched by two grooves 21 and has wider parts and narrower parts in the longitudinal direction is formed on a double hetero substarate wherein an N type buffer layer 11, a non-doped active layer 12, and a P type clad layer 13 are formed on a substrate 10. Successively, a P type and an N type current block layer 14 and 15, a P type buried layer 16, and a P type cap layer 17 are formed by performing the second crystal growth. At this time, the current block layers 14 and 15 do not grow at the narrower parts 20a of the mesa stripe 20. When electrodes 31 and 32 are provided on an element of such a constitution, the electrode 31 is biased positively, and the electrode 32 negatively, the element operates as a photo bi-stable element having two levels stable for a current input or a photo input. |
