| 摘要 |
PURPOSE:To provide the optical function element which is compact and is suitable for integration by shifting a part of pumping light into a 1st optical waveguide and controlling the threshold intensity of the bistable operation of signal light. CONSTITUTION:The distribution feedback (DFB) type bistable element of an optical waveguide structure and the optical wavegude 4 for the signal light of this DFB type optical bistable element and a nonlinear directional coupler consisting of the optical waveguide 8 for pumping light are combined, by which the bistable operation and the operation of the nonlinear directional coupler are provided in combination. A part of the pumping light intensity Ip, therefore, shifts from the optical waveguide 8 according to an increase in the signal light intensity Ii of the optical waveguide 4. The threshold Ith 1 of the signal light intensity Ii which makes the bistable operation is consequently decreased. The decrease in the threshold Ith 1 of the signal light intensity Ii of this time is controlled by the light intensity Ip of the pumping light propagating in the optical wavegude 8 and the coupling coefft., etc., between the optical waveguides 4 and 8. Thus, the optical function element which is compact and is suitable for integration is obtd. |
