SEMICONDUCTOR LIGHT-EMITTING ELEMENT, OPTICAL DETECTING DEVICE, OPTICAL INFORMATION DETECTING DEVICE, PROJECTOR AND OPTICAL FIBER MODULE

摘要

PURPOSE:To effectively reflect lights of various directions in a wide wavelength range, by specifying the film thickness sum value of each semiconductor layer, by using the wavelength of light emitted from a PN junction part, and the refractive index of each semiconductor layer constituting an unit semiconductor layer. CONSTITUTION:The multilayered reflecting film layer 14 of a semiconductor light-emitting element B is formed by alternately laminating semiconductor layers 14a having a refractive index n1 and semiconductor layers 14b having a refractive index n2 which refractive indexes are smaller than that of an active layer 4 and that of a lower clad layer 3. The center wavelength of a light emitted from the active layer lambda0 is A The sum of film thickness of the semiconductor layers l4a having the refractive index n1 is set smaller than lambda0/(4n1), and the sum of the film thickness of the semiconductor layers 14b having the refractive index n2 is set larger than lambda0/(4n2). The reflection peak wavelength range is extended toward the long wavelength side and the short wavelength side, and the range can be widened. Thereby effective reflection can be realized in the range from the vertically incident light to the multilayered reflecting film layer 14 to the obliquely incident light having an angle to the layer.