PURPOSE: To obtain an optical logical circuit which includes an optical AND circuit and performs optical logical operations by composing a photoelectromotive force element which is excited with light propagating in the 1st light guide and an electrode which is provided where the 2nd and the 3rd light guides are close to each other and applied with the voltage that the photoelectromotive force element generates.
CONSTITUTION: One terminal part of the 3rd light guide 13 is close to part of the 2nd light guide 12 and the remainder is at distance from the 2nd light guide 12. The part where the 2nd light guide 12 and the 3rd light guide 13 are close to each other constitutes a directional coupler and a couple of electrodes 14 are provided on the light guide part. Both terminals of the photoelectromotive force element 15 are connected to the electrode 14 through a wiring pattern 16 and the electromotive force of the element 15 is applied to the electrode 14. Then when input light signals IinA and IinB are "0" and "0", "1" and "0", or "0" and "1", an output light signal Iout is "0" and only when the inputs are "1" and "1", the output is "1".
INOUE NAOHISA
MATANO MASAHARU
YAMASHITA MAKI
