Pinned dynamic electro-optical phase shifter
A semiconductor electro-optical phase shifter may include a substrate, an optical waveguide segment ( 12 ) formed on the substrate, and first and second zones of opposite conductivity types configured to form a first bipolar junction perpendicular to the substrate. The phase shifter may also include a dynamic control structure configured to reverse bias the first junction and a static control structure configured to direct a quiescent current in the second zone, parallel to the first junction.
1. A method of phase shifting an optical wave in an optical waveguide on a substrate, the method comprising:
producing a quiescent current flowing parallel to a first bipolar junction and forward biasing a second bipolar junction, the first bipolar junction and the second bipolar junction sharing a first zone; and
reverse biasing the first bipolar junction using a modulation signal.
2. The method according to claim 1 , wherein the first bipolar junction comprises the first zone and a second zone of opposite conductivity; and wherein the second bipolar junction comprises a fourth zone having a same conductivity as the second zone, and shares the second zone.
3. The method according to claim 2 , wherein the second bipolar junction extends in a direction transverse to the first bipolar junction.
4. The method according to claim 2 , wherein the optical waveguide further comprises a third bipolar junction sharing the first zone with the first and second bipolar junctions and comprising a third zone having a same conductivity as the second zone.
5. The method according to claim 4 , further comprising reverse biasing the third bipolar junction using the modulation signal.
6. The method according to claim 4 , wherein the third bipolar junction extends in a parallel direction to the first bipolar junction.
7. The method according to claim 1 , wherein the optical waveguide defines an optical axis; and wherein the first bipolar junction extends transverse to the optical axis.
8. The method according to claim 1 , wherein the optical waveguide defines an optical axis; and wherein the first bipolar junction extends parallel to the optical axis.
9. The method according to claim 1 , wherein the producing the quiescent current comprises generating the quiescent current with a static control structure.
10. The method according to claim 1 , wherein reverse biasing the first bipolar junction comprises generating the modulation signal with a dynamic control structure.
11. A method of phase shifting an optical wave in an optical waveguide on a substrate and comprising a first bipolar junction and a second bipolar junction sharing a first zone with the first bipolar junction, the method comprising:
operating a static control structure to produce a quiescent current flowing parallel to the first bipolar junction and forward biasing the second bipolar junction; and
operating a dynamic control structure coupled to the static control structure to reverse bias the first bipolar junction using a modulation signal.
12. The method according to claim 11 , wherein the first bipolar junction comprises the first zone and a second zone of opposite conductivity; and wherein the second bipolar junction comprises a fourth zone having a same conductivity as the second zone, and shares the first zone.
13. The method according to claim 12 , wherein the second bipolar junction extends in a direction transverse to the first bipolar junction.
14. The method according to claim 12 , wherein the optical waveguide further comprises a third bipolar junction sharing the first zone with the first and second bipolar junctions and comprising a third zone having a same conductivity as the second zone.
15. The method according to claim 14 , further comprising reverse biasing the third bipolar junction using the modulation signal.
16. The method according to claim 14 , wherein the third bipolar junction extends in a parallel direction to the first bipolar junction.
17. The method according to claim 11 , wherein the optical waveguide defines an optical axis; and wherein the first bipolar junction extends transverse to the optical axis.
18. The method according to claim 11 , wherein the optical waveguide defines an optical axis; and wherein first bipolar junction extends parallel to the optical axis.
19. A method for making a phase shifter for an optical wave in an optical waveguide on a substrate comprising:
forming a first bipolar junction and a second bipolar junction in the optical waveguide so that the first and second bipolar junctions share a first zone;
coupling a static control structure to produce a quiescent current flowing parallel to the first bipolar junction and to forward bias the second bipolar junction; and
coupling a dynamic control structure to reverse bias the first bipolar junction using a modulation signal.
20. The method according to claim 19 , wherein the first bipolar junction comprises the first zone and a second zone of opposite conductivity; and wherein the second bipolar junction comprises a fourth zone having a same conductivity as the second zone, and shares the first zone.
21. The method according to claim 20 , wherein the second bipolar junction extends in a direction transverse to the first bipolar junction.
22. The method according to claim 20 , further comprising forming a third bipolar junction sharing the first zone with the first and second bipolar junctions and comprising a third zone having a same conductivity as the second zone.
23. The method according to claim 22 , wherein the third bipolar junction extends in a parallel direction to the first bipolar junction.
24. The method according to claim 19 , wherein the optical waveguide defines an optical axis; and wherein first bipolar junction extends transverse to the optical axis.
25. The method according to claim 19 , wherein the optical waveguide defines an optical axis; and wherein the first bipolar junction extends parallel to the optical axis.
26. A method of operating a photonic circuit, the method comprising:
using a modulation signal, applying a reverse bias to a first p/n junction formed between a first zone and a second zone, the reverse bias depleting a portion of the first zone; and
applying a forward bias to a second p/n junction formed between the first zone and a third zone to generate a current through the first zone and the second p/n junction, the reverse bias controlling an amount of the current.
27. The method according to claim 26 , wherein the photonic circuit comprises an optical waveguide having an optical axis, and wherein the first p/n junction extends transverse to the optical axis.
28. The method according to claim 26 , wherein the photonic circuit comprises an optical waveguide having an optical axis, and wherein the first p/n junction extends parallel to the optical axis.
29. The method according to claim 26 , wherein the current is generated using a static control structure.
30. The method according to claim 1 , further comprising generating the modulation signal with a dynamic control structure.