| 摘要 |
PURPOSE:To enable only a light of a desired wavelength to be outputted, by providing a first active layer about in parallel with a light taking-out face, and by providing a second active layer on the opposite side to the light taking-out face of the first active layer, and further, by providing a reflection layer which reflects the light received from the first active layer and transmits the light received from the second active layer. CONSTITUTION:A selective reflection layer 22 is provided between an active layer 26 and an active layer 18, which is provided on the opposite side to the side of a light taking-out face 38 of the active layer 26. The selective reflection layer 22 reflects entirely the light of its wavelength lambda1, which generates in the active layer 26 and proceeds to the side of the active layer 18, and transmits most of the light of its wavelength lambda2, which generates in the active layer 18 and proceeds to the active layer 26. Also, the active layer 18 is formed with the material having the smaller energy gap of electron than the active layer 26, and the light energy generated from the active layer 18 is made less than the one generated form the active layer 26. Thereby, the light generated from the active layer 26 is prevented from being absorbed in the active layer 18 to generate a light, and the light generated form the active layer 18 is prevented from being absorbed in the active layer 26 to generate a light. |
