| 摘要 |
PURPOSE:To remove the maximum order supermode by limiting the widths of a semiconductor layer and a waveguide corresponding to the difference in refractive indexes between the waveguide and semiconductor layers in a waveguide adjacent to the waveguide. CONSTITUTION:A semiconductor layer 2, a lower clad layer 4, an active layer 5, an active region 6, and an upper clad layer 7 are formed on a semiconductor substrate 1. A 10-string waveguide 11 made of 10-string stripe grooves formed by etching the layer 2 is limited in width W in response to the value of the difference of the refractive indexes of the waveguide 11 and the layer 2 between the adjacent waveguides 11 to the waveguide 11. Thus, since an intrinsic mode generated by optical coupling, i.e., the maximum order supermode is removed, the reference mode having a gain larger next to the maximum order supermode can readily rise, thereby increasing the farther visual field image perpendicularly to the end face to the maximum. |
