Thermoopic type variable optical attenuator and array type variable optical attentuator using this

摘要

A thermo optical type variable optical attenuator suitable for application in an array type variable optical attenuator that realizes low crosstalk between neighboring waveguides in the array is provided. A thermo optical type variable optical attenuator 100 using optical material having negative optical effect provides a multimode optical propagating part 3 disposed via a tapered part 2 and a tapered part 7 between single mode optical waveguides 1 and 8 . A thin-film heater 4 is disposed above the multimode optical propagating part 3 at an angle of inclination beta in relation to the direction of light propagation along a first optical waveguide 50 . Moreover, a second optical waveguide 9 optically coupled with a side face 3 S 1 of the multimode optical propagating part 3 is provided at an angle of inclination 2 beta in relation to the direction of light propagation along the first optical waveguide 50.