| 摘要 |
<p>A high output power semiconductor laser for communications realizing a high optical output power with a low operating current, high optical fiber coupling efficiency and an excellent high-temperature characteristic without impairing mass productivity. An n-type InGaAsP mode-expansion layer (102) is provided between an n-type InP substrate (101) and an n-type InP clad layer (103). An n-side optical waveguide layer (104) and a p-side optical waveguide layer (106) are different from each other in their compositions and/or layer thicknesses. The mode-expansion layer (102) is a high refractive index layer composed of one or more layers having different refraction indexes from that of the n-type clad layer (103). The effective refractive index of the mode-expansion layer (102) is higher than that of a p-type clad layer (107). The distance between the n-side optical waveguide layer (104) and the mode-expansion layer (102) is 0.2 mum or more.</p> |
