| 摘要 |
PURPOSE:To display good efficiency characteristic to an optical waveguide structure sufficiently and to enable the operation with low light power by specifying the light absorption coefficient of a material and optimizing the absorption of control light. CONSTITUTION:As for, for example, an element A, signal light 7 is branched by a branch part 11 into two waveguides and multiplexed by a multiplexing part 12 into one light beam again. Namely, this part forms a Mach-Zehnder interference system. The difference in effective optical path length between both arms of this Mach-Znhnder interference system is different by a half of the wavelength lambda2 of the signal light 7, so the light is converted to a radiation mode by the multiplexing part 12 and therefore not outputted. When signal light 8 is made incident at the same time through a directional coupling part 13, on the other hand, a heterostructure 5 absorbs the signal light lambda to vary its refractive index, so the element A generates its output. Namely, the output of the element A is the result of logical operation between the inputs 7 and 8. Consequently, the operation with the low light power is enabled. |
