Method and system for a silicon-based optical phase modulator with high modal overlap
View Patent ↗Methods and systems for a silicon-based optical phase modulator with high modal overlap are disclosed and may include, in an optical modulator having a rib waveguide in which a cross-shaped depletion region separates four alternately doped sections: receiving an optical signal at one end of the optical modulator, modulating the received optical signal by applying a modulating voltage, and communicating a modulated optical signal out of an opposite end of the modulator. The modulator may be in a silicon photonically-enabled integrated circuit which may be in a complementary-metal oxide semiconductor (CMOS) die. An optical mode may be centered on the cross-shaped depletion region. The four alternately doped sections may include: a shallow depth p-region, a shallow depth n-region, a deep p-region, and a deep n-region. The shallow depth p-region may be electrically coupled to the deep p-region periodically along the length of the modulator.
1. A method for optical communication, the method comprising:
in a rib waveguide having, in a cross-sectional plane perpendicular to a light path of the rib waveguide, a cross-shaped depletion region and four alternately doped sections separated by the cross-shaped depletion region, wherein the four alternately doped sections comprise a shallow depth p-region, a shallow depth n-region, a deep p-region, and a deep n-region, and wherein the shallow depth p-region is electrically coupled to the deep p-region periodically along a length of the rib waveguide where a portion of the shallow depth n-region is removed and the shallow depth p-region extends across a width of the rib waveguide:
receiving an optical signal at one end of the rib waveguide; and
modulating the received optical signal by applying a modulating voltage to the rib waveguide.
2. The method according to claim 1 , wherein the rib waveguide is in a silicon photonically-enabled integrated circuit.
3. The method according to claim 2 , wherein the silicon photonically-enabled integrated circuit is in a complementary-metal oxide semiconductor (CMOS) die.
4. The method according to claim 1 , wherein an optical mode from the received optical signal is centered on the cross-shaped depletion region.
5. The method according to claim 1 , wherein the shallow depth n-region is electrically coupled to the deep n-region periodically along the length of the optical modulator where a portion of the shallow depth p-region is removed and the shallow depth n-region extends across the width of the rib waveguide.
6. The method according to claim 1 , wherein a rib section of the rib waveguide comprises the shallow depth p-region and the shallow depth n-region.
7. The method according to claim 1 , wherein a slab section of the rib waveguide comprises the deep p-region and the deep n-region.
8. The method according to claim 1 , wherein highly doped layers are on top of the shallow depth p-region and the shallow depth n-region.
9. A system for communication, the system comprising:
a rib waveguide having, in a cross-sectional plane perpendicular to a light path of the rib waveguide, a cross-shaped depletion region and four alternately doped sections separated by the cross-shaped depletion region, wherein the four alternately doped sections comprise a shallow depth p-region, a shallow depth n-region, a deep p-region, and a deep n-region, and wherein the shallow depth p-region is electrically coupled to the deep p-region periodically along a length of the rib waveguide where a portion of the shallow depth n-region is removed and the shallow depth p-region extends across a width of the rib waveguide, the rib waveguide being operable to:
receive an optical signal at one end of the rib waveguide; and
modulate the received optical signal by applying a modulating voltage to the rib waveguide.
10. The system according to claim 9 , wherein the rib waveguide is in a silicon photonically-enabled integrated circuit in a complementary-metal oxide semiconductor (CMOS) die.
11. The system according to claim 9 , wherein an optical mode from the received optical signal is centered on the cross-shaped depletion region.
12. The system according to claim 9 , wherein the shallow depth n-region is electrically coupled to the deep n-region periodically along the length of the optical modulator where a portion of the shallow depth p-region is removed and the shallow depth n-region extends across the width of the rib waveguide.
13. The system according to claim 9 , wherein a rib section of the rib waveguide comprises the shallow depth p-region and the shallow depth n-region.
14. The system according to claim 9 , wherein a slab section of the rib waveguide comprises the deep p-region and the deep n-region.
15. The system according to claim 9 , wherein highly doped layers are on top of the shallow depth p-region and the shallow depth n-region.
16. A system for communication, the system comprising:
a semiconductor die having a rib waveguide, the rib waveguide comprising:
a slab section with a lower n-region and a lower p-region;
a rib section comprising an upper n-region and an upper p-region, the upper n-region above the lower p-region and the upper p-region above the lower n-region; and
a cross-shaped depletion region, in a cross-sectional plane perpendicular to a light path of the rib waveguide, upon which an optical mode is centered, the cross-shaped depletion region formed by the lower n-region, the lower p-region, the upper n-region, and the upper p-region, wherein the upper p-region is electrically coupled to the lower p-region periodically along a length of the rib waveguide where a portion of the upper n-region is removed and the upper p-region extends across a the width of the rib waveguide.
17. A method for optical communication, the method comprising:
in a waveguide having, in a cross-sectional plane perpendicular to a light path of the rib waveguide, a cross-shaped depletion region and four alternately doped sections separated by the cross-shaped depletion region, wherein the four alternately doped sections comprise a shallow depth p-region, a shallow depth n-region, a deep p-region, and a deep n-region, and wherein the shallow depth n-region is electrically coupled to the deep n-region periodically along a length of the rib waveguide where a portion of the shallow depth p-region is removed and the shallow depth n-region extends across a width of the rib waveguide:
receiving an optical signal at one end of the rib waveguide; and
modulating the received optical signal by applying a modulating voltage to the rib waveguide.
18. The method according to claim 17 , wherein the rib waveguide is in a silicon photonically-enabled integrated circuit.
19. The method according to claim 18 , wherein the silicon photonically-enabled integrated circuit is in a complementary-metal oxide semiconductor (CMOS) die.
20. The method according to claim 17 , wherein an optical mode from the received optical signal is centered on the cross-shaped depletion region.
21. The method according to claim 17 , wherein a rib section of the rib waveguide comprises the shallow depth p-region and the shallow depth n-region.
22. The method according to claim 17 , wherein a slab section of the rib waveguide comprises the deep p-region and the deep n-region.
23. The method according to claim 17 , wherein highly doped layers are on top of the shallow depth p-region and the shallow depth n-region.
24. A system for communication, the system comprising:
a rib waveguide having, in a cross-sectional plane perpendicular to a light path of the rib waveguide, a cross-shaped depletion region and four alternately doped sections separated by the cross-shaped depletion region, wherein the four alternately doped sections comprise a shallow depth p-region, a shallow depth n-region, a deep p-region, and a deep n-region, and wherein the shallow depth n-region is electrically coupled to the deep n-region periodically along a length of the rib waveguide where a portion of the shallow depth p-region is removed and the shallow depth n-region extends across a width of the rib waveguide, the rib waveguide being operable to:
receive an optical signal at one end of the rib waveguide; and
modulate the received optical signal by applying a modulating voltage to the rib waveguide.
25. The system according to claim 24 , wherein the rib waveguide is in a silicon photonically-enabled integrated circuit in a complementary-metal oxide semiconductor (CMOS) die.
26. The system according to claim 24 , wherein an optical mode from the received optical signal is centered on the cross-shaped depletion region.
27. The system according to claim 24 , wherein a rib section of the rib waveguide comprises the shallow depth p-region and the shallow depth n-region.
28. The system according to claim 24 , wherein a slab section of the rib waveguide comprises the deep p-region and the deep n-region.
29. The system according to claim 24 , wherein highly doped layers are on top of the shallow depth p-region and the shallow depth n-region.