| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-speed digital optical switch that is driven at a low voltage. SOLUTION: The digital optical switch includes: a substrate comprising a material of one of KTaO<SB>3</SB>, KNbO<SB>3</SB>and KTa<SB>1-x</SB>Nb<SB>x</SB>O<SB>3</SB>(0<x<1); a core waveguide comprising a material of one of K<SB>1-y</SB>Li<SB>y</SB>Ta<SB>1-x</SB>Nb<SB>x</SB>O<SB>3</SB>(0<x<1, 0<y<1) and KTa<SB>1-x</SB>Nb<SB>x</SB>O<SB>3</SB>(0<x<1) placed on the substrate; a three-dimensional waveguide having clad layers made of K<SB>1-y</SB>Li<SB>y</SB>Ta<SB>1-x</SB>Nb<SB>x</SB>O<SB>3</SB>(0<x<1, 0<y<1) having a refractive index slightly smaller than that of the core waveguide; an electrode for applying an electric field to the core waveguide, the electrode formed at least one of below the lower clad layer or above the upper clad layer of the three-dimensional waveguide; and a Y branching waveguide composed of the three-dimensional optical waveguide and includes a first input optical waveguide having an input end for receiving a transmitted optical signal, a second output optical waveguide and a third output optical waveguide branched from the first input waveguide, and the electrodes placed on the second output optical waveguide and on the third output optical waveguide. COPYRIGHT: (C)2008,JPO&INPIT |
