| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an acousto-optical tunable filter of which the wavelength dependency of a coupling length is improved. <P>SOLUTION: The acousto-optical tunable filter is provided with a substrate, first and second surface acoustic waveguides formed in parallel on the substrate, a first IDT formed on the one end side of the first surface acoustic waveguide and generating the surface acoustic wave, an optical waveguide formed on the second surface acoustic waveguide and a polarization beam splitter or a polarizer arranged on the respective input side and output side of the optical waveguide or on the one out of them and separating or synthesizing a TM mode and a TE mode of an optical wavelength division multiplexing signal, and is constructed so as to make propagation characteristics of the first and second surface acoustic waveguides different from each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
