SEMICONDUCTOR OPTICAL DEVICE

摘要

PURPOSE:To improve the characteristics as a diode, extinction ratio characteristic and light switching characteristic by providing doping layers having a high doping concn. and small thickness only at the boundary between non-doped layers and the doping layers. CONSTITUTION:The p-InP layers 14 having a high doping concn. and small thickness are provided between the p-InP clad layers 3 and the i-InP clad layers 4 which are the non-doped layers and the n-InP layers 16 having a high doping concn. and small thickness are provided on the n side. These layers are respectively provided in order to control the diffusion fronts of the p type and n type dopants. Since the thicknesses of these layers are required to be as small as from several nm to about several 10nm, the propagation loss of light is not adversely affected. Further the diffusion fronts of the dopants are uniformly controlled and formed by the presence of such layers and, therefore, the doping amt. of the p-InP clad layers 3 and the n-InP clad layers is made smaller than heretofore. As a result, the propagation loss is eventually made lower than the propagation loss of the conventional structures.