Optical waveguide device and module
In a waveguide device, unnecessary optical power is appropriately terminated. According to an embodiment of the present invention, the waveguide device has a termination structure filled with a light blocking material to terminate light from a waveguide end. In the termination structure, a cladding and a core are removed to form a groove on an optical waveguide. The groove is filled with a material (light blocking material) that attenuates the intensity of light. Thus, light input to the termination structure is attenuated by the light blocking material, suppressing crosstalk which possibly effects on other optical devices. Thus, such a termination structure can restrain crosstalk occurred in optical devices integrated in the same substrate and can also suppress crosstalk which possibly effects on any other optical device connected directly to the substrate.
1. A waveguide device, comprising:
a termination structure comprised of a light blocking material, the light blocking material bounding a passageway extending longitudinally thereinto to an end face;
a waveguide having a terminal end comprising a taper portion with a waveguide width decreasing toward a terminal point, the taper portion having a taper angle that is substantially equal to or smaller than a critical angle at which adiabatic transition occurs, the terminal end of the waveguide being positioned within the passageway, a gap being formed by the passageway longitudinally between the terminal point of the waveguide and the end face of the passageway;
wherein light from the waveguide enters the light blocking material through the end face of the passageway at an oblique incidence angle, and
wherein a width of the passageway is constant at least in a region corresponding to the taper portion of the waveguide.
2. The waveguide device according to claim 1 , wherein the angle of incidence is substantially equal to or larger than a Brewster's angle.
3. The waveguide device according to claim 1 wherein the light blocking material comprises a material that absorbs or scatters light from the terminal end of the waveguide.
4. The waveguide device according to claim 1 , comprising: at least one of a Mach Zehnder optical switch, a variable attenuator, an optical splitter, and an arrayed waveguide grating.
5. A module obtained by multichip integration using waveguide devices according to claim 1 .
6. The waveguide device recited in claim 1 , wherein the end face is planar.
7. A waveguide device, comprising:
a termination structure comprised of a light blocking material, the light blocking material bounding a passageway extending longitudinally thereinto to an end face;
a waveguide having a terminal end comprising a taper portion with a waveguide width decreasing toward a terminal point, the taper portion having a taper angle that is substantially equal to or smaller than a critical angle at which adiabatic transition occurs, the terminal end of the waveguide being positioned within the passageway, a gap being formed at a cladding layer by the passageway longitudinally between the terminal point of the waveguide and the end face of the passageway;
wherein light from the waveguide enters the light blocking material through the end face of the passageway at an oblique incidence angle; and
wherein a width of the passageway is constant at least in a region corresponding to the taper portion of the waveguide.
8. The waveguide device according to claim 7 , wherein the angle of incidence is substantially equal to or larger than a Brewster's angle.
9. The waveguide device according to claim 7 , wherein the light blocking material comprises a material that absorbs or scatters light from the terminal end of the waveguide.
10. The waveguide device according to claim 7 , comprising: at least one of a Mach Zehnder optical switch, a variable attenuator, an optical splitter, and an arrayed waveguide grating.
11. A module obtained by multichip integration using waveguide devices according to claim 7 .
12. The waveguide device recited in claim 7 , wherein the end face is planar.