| 摘要 |
PURPOSE:To enhance sensibility for bi-directional light transmission by a single optical fiber, by providing diffused layers with different depths in a compound semiconductor layer having composition slope to reduce the energy gap of a light detection part less than that of a light emission part. CONSTITUTION:An N type GaAsP layer 2 on a N type GaAs substrate 1 has continuously varying composition slope. A P type layer 8 is formed thereon by Zn diffusion for the light emission part and P type layer 7 for the light detection part in the same way. The light detection part has an energy gap smaller than that of the light emission part. The impression of negative voltage on an N type electrode 8 causes light emission having the center in wave length corresponding to the energy gap with light transmitted through the core part 12 of an optical fiber 13. On the other hand, a P side electrode 7 formed in negative serves as an LED. Thus, sensibility is enhanced with bi-directional transmission available by a single optical fiber. |
