Manufacturing method of optical device and optical device
A method of manufacturing an optical device involves forming patterns on a dielectric substrate. The patterns include a waveguide pattern having a folded part, a conductor pattern positioned on an outer peripheral side of the folded part, and a dummy pattern that connects the folded part and the conductor pattern. The method further involves performing heat diffusion processing on the dielectric substrate on which the patterns have been formed at the forming, to make the waveguide pattern into an optical waveguide.
1. A method of manufacturing an optical device, comprising:
forming patterns on a dielectric substrate, the patterns including a waveguide pattern having a folded part, a conductor pattern positioned on an outer peripheral side of the folded part, and a dummy pattern that connects the folded part and the conductor pattern;
performing heat diffusion processing on the dielectric substrate on which the patterns have been formed at the forming, to make the waveguide pattern into an optical waveguide and to make the dummy pattern into a dummy waveguide; and
forming a groove, on the dielectric substrate, along an outer periphery of the folded part of the optical waveguide formed at the performing so as to separate the optical waveguide and the dummy waveguide.
2. The method of manufacturing according to claim 1 , wherein the forming patterns includes forming a plurality of dummy patterns.
3. The method of manufacturing according to claim 1 , wherein the forming patterns includes forming the dummy pattern to have a width wider than a width of the waveguide pattern.
4. The method of manufacturing according to claim 1 , further comprising cutting, with respect to the dielectric substrate on which the heat diffusion processing has been performed at the performing, a portion in which the conductor pattern has been formed at the forming patterns, to remove the portion.
5. The method of manufacturing according to claim 1 , wherein
the forming patterns includes forming the waveguide pattern to include parallel waveguides respectively having the folded part, and the dummy pattern that connects each of the parallel waveguides to the conductor pattern, and
the forming a groove includes forming a first groove along an outer periphery of an outer folded-waveguide among the parallel waveguides, and forming a second groove along an outer periphery of an inner folded-waveguide among the parallel waveguides.
6. The method of manufacturing according to claim 5 , wherein the forming a groove further includes forming a third groove along an inner periphery of the inner folded-waveguide.
7. The method of manufacturing according to claim 6 , wherein the third groove is formed such that a distance between the outer folded-waveguide and the second groove is equal to a distance between the inner folded-waveguide and the third groove.
8. The method of manufacturing according to claim 6 , wherein the third groove is formed such that a distance between the first groove and the second groove is equal to a distance between the second groove and the third groove.
9. The method of manufacturing according to claim 5 , further comprising forming a signal electrode on the dielectric substrate along the optical waveguide formed at the performing, wherein
the forming a groove includes forming the first groove, the second groove, and a third groove in an entire interacting portion of the optical waveguide and the signal electrode, the third groove being formed along an inner periphery of the inner folded-waveguide.
10. The method of manufacturing according to claim 5 , wherein a curvature radius of the outer folded-waveguide is 4 mm or less.
11. The method of manufacturing according to claim 5 , wherein the forming patterns includes forming the parallel waveguides to have at least two pairs of parallel folded parts, conductor patterns respectively positioned on an outer peripheral side of each of the pairs of parallel folded parts, and dummy patterns that respectively connect the pairs of parallel folded parts to the conductor patterns, respectively.
12. The method of manufacturing according to claim 11 , wherein the forming a groove includes forming the groove along an outer periphery of each of folded part comprising the pairs of parallel folded parts.
13. The method of manufacturing according to claim 1 , wherein the forming patterns includes forming the dummy pattern such that the dummy pattern connects a straight part near the folded part in the waveguide pattern to the conductor pattern.
14. The method of manufacturing according to claim 13 , wherein the forming patterns includes forming the dummy pattern such that an angle between the straight part and the dummy pattern is 30 degrees or more.
15. The method of manufacturing according to claim 13 , wherein the forming patterns includes forming the dummy pattern to have a width narrower than a width of the straight part.
16. The method of manufacturing according to claim 13 , further comprising forming a groove on the dielectric substrate along an outer periphery of the straight part and the folded part formed at the forming patterns.
17. The method of manufacturing according to claim 16 , wherein the forming a groove includes forming the groove such that a distance between the straight part and the groove gradually decreases to a point of connection between the straight part and the groove.