| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a waveguide type optical attenuator having extremely low dependence on polarized waves. <P>SOLUTION: The attenuator is equipped with input optical waveguides 11a, 11b, first optical coupler 12, first optical waveguide pair 13a, 13b, second optical coupler 14, second optical waveguide pair 15a, 15b, third optical coupler 16, third optical waveguide pair 17a, 17b, fourth optical coupler 18, and output optical waveguides 19a, 19b on a substrate 10. The first optical waveguide pair, second optical waveguide pair and third optical waveguide pair are provided with variable phase controlling means 20, 22, 23, respectively. The first optical waveguide pair and the third optical waveguide pair are provided with birefringent controlling means 21, 24, respectively. <P>COPYRIGHT: (C)2004,JPO</p> |
