| 摘要 |
PURPOSE: To make it possible to deal sufficiently with optical communication technology by setting the band end energy of a first semiconductor layer larger than twice the energy the operation wavelength corresponding to the sub-band intervals of the first semiconductor layer and setting the energy of the operation wavelength corresponding to the sub-band intervals at a specific value or higher. CONSTITUTION: A quantum well structure consisting of a GaN quantum well layer 13 and an AIN first barrier layer 14 is formed on a GaN layer. The band end energy Edge of the GaN well layer 13 is set larger than twice the energy Eop of the operation wavelength corresponding to the sub-band intervals of the GaN well layer 13. The band end energy is larger than the energy of two photons if the energy is set in such a manner and, therefore, the probability that the photons are absorbed is extremely low. Eop is required to be set at >=0.75eV which is the band gap of InGaAs to be lattice matched with, for example, InP if the materials and wavelength bands commonly used in optical communication are taken into consideration. |
