| 摘要 |
PURPOSE:To convert beams having a short wavelength efficiently into beams having a desired long wavelength by holding a semiconductor having specified forbidden band width by two layers of semiconductors having forbidden band width wider than said semiconductor. CONSTITUTION:A P-In0.53Ga0.47As layer 2 is formed onto a P-InP layer 1, and a P-InP layer 3 is shaped onto the layer 2. The forbidden band width of the layers 1 and 3 is made larger than that of the layer 2, and the acceptor levels of the layers 1 and 3 are positioned at the positions of energy higher than the acceptor level of the layer 2. Consequently, when the layer 1 and the layer 2 are brought into contact, holes in the vicinity of the surface of the layer 1 flow in to the vicinity of the surface of the layer 2, and reach to thermal equilibrium. When the layer 1 is irradiated by beams having energy higher than the forbidden band width of InP, electrons are collected to an electron well. The electrons recombine with holes in the electron well, and beams having the energy of the forbidden band width of In0.53Ga0.47As are emitted. The wavelength of the beams is 1.6mum long, thus converting projecting beams having a short wavelength into beams having a desired long wavelength. |
