Optical waveguide device, and optical modulation device and optical transmission apparatus using same
An optical waveguide device includes an optical waveguide formed on a substrate, in which an optical modulator section that modulates a light wave propagating through the optical waveguide is formed in a part of the optical waveguide, in which a first dielectric layer covers the optical waveguide, and a second dielectric layer formed of a different material from the first dielectric layer is disposed on the first dielectric layer in a part of the optical waveguide excluding the optical modulator section.
1 . An optical waveguide device including a protruding optical waveguide formed on a substrate with a thickness of 1 μm or less, in which an optical modulator section that modulates a light wave propagating through the protruding optical waveguide is formed in a part of the protruding optical waveguide,
wherein a first dielectric layer covers all of the protruding optical waveguide,
a second dielectric layer formed of a different material from the first dielectric layer is disposed on the first dielectric layer and is not formed anywhere in the optical modulator section,
a thickness of the first dielectric layer is 1 μm or less,
a thickness of the second dielectric layer is 2 μm or greater, and
a Young's modulus of the second dielectric layer is less than a Young's modulus of the first dielectric layer.
2 . The optical waveguide device according to claim 1 ,
wherein the first dielectric layer is formed of an inorganic material having a lower refractive index than a refractive index of a material constituting the protruding waveguide, and the second dielectric layer is formed of an organic material having a lower refractive index than the refractive index of the material constituting the protruding optical waveguide.
3 . The optical waveguide device according to claim 1 ,
wherein a spot size converter is formed in an end portion of the protruding optical waveguide, and the first dielectric layer and the second dielectric layer are used as a part of constituents of the spot size converter.
4 . The optical waveguide device according to claim 1 ,
wherein the substrate is a thin film layer formed on a surface of a reinforcing substrate.
5 . An optical modulation device comprising:
the optical waveguide device according to claim 1 ; a case accommodating the optical waveguide device; and
an optical fiber through which a light wave is input into the protruding optical waveguide or output from the protruding optical waveguide.
6 . The optical modulation device according to claim 5 ,
wherein the optical waveguide device includes a modulation electrode for modulating a light wave propagating through the protruding optical waveguide, and an electronic circuit that amplifies a modulation signal to be input into the modulation electrode is provided inside the case.
7 . An optical transmission apparatus comprising:
the optical modulation device according to claim 6 ;
a light source that inputs a light wave into the optical modulation device; and
an electronic circuit that outputs a modulation signal to the optical modulation device.