| 摘要 |
PURPOSE:To provide the optical functional element which can make input light and output light into the same direction by setting the forbidden band width of a semiconductor material constituting a light emitting part larger than the main peak energy of input light and simultaneously using the light emitting part thereof as an input window. CONSTITUTION:A phototransistor structure of an npn heterojunction is used as a light receiving part and an light emitting diode structure of a p-n homojunction is used as the light emitting part. The input light A is made incident from the window 50 in the upper part of the light emitting part II and arrives at the light receiving part I. The wavelength corresponding to the forbidden band width of the light emitting part II is about 670 nm and, therefore, if the light of this wavelength is used as the input light, this light arrives at the light receiving part I without receiving absorption in the light emitting part II. The output light B is outputted upward through the window 50 from the light emitting part II. A part of this output light arrives at the light receiving part I and the nonlinear input/output characteristics are obtd. by the optical feedback effect thereof. |
