Patent ID: 7203411
Filing Date: 2007-04-10
Classification: G02F

Abstract:
1. A thermo optical type variable optical attenuator that uses an optical material having negative optical effects, the optical attenuator comprising: a first optical waveguide further comprising a first single mode light propagating part that propagates incident light, a second single mode light propagating part that propagates output light, a multimode light propagating part disposed between the first and the second single mode propagating parts, a first tapered part disposed between the first single mode propagating part and the multimode propagating part, and a second tapered part disposed between the second single mode propagating part and the multimode propagating part; a thin-film heater arranged above the multimode light propagating part inclined at an angle β in relation to the direction of propagating of light output from the first optical waveguide; and a second optical waveguide further comprising a multimode light receiving part disposed on one side of the multimode light propagating part inclined at an angle