High-speed photonic modulator designs
View Patent ↗An optical device includes a microdisk optical resonator element. The microdisk resonator element is formed on a substrate and has upper and lower portions respectively distal and proximal the substrate. An arcuate semiconductor contact region partially surrounds the microdisk resonator element. A first modulator electrode is centrally formed on the upper portion of the microdisk resonator element, and a second modulator electrode is formed on the arcuate contact region. A laminar semiconductor region smaller in thickness than the microdisk resonator element separates the arcuate contact region from the microdisk resonator element and is formed on the substrate so as to electrically connect the arcuate contact region to the lower portion of the microdisk resonator element.
1. An optical device, comprising:
a microdisk resonator element containing a semiconductor junction;
an arcuate semiconductor region displaced from and partially surrounding the resonator element;
a central modulator electrode positioned on a central portion of the resonator element for making contact with one side of the semiconductor junction;
a peripheral modulator electrode positioned on the arcuate semiconductor region for making contact with the other side of the semiconductor junction; and
a laminar semiconductor pedestal smaller in thickness than the resonator element and extensive between at least a portion of the resonator element and the arcuate contact region so as to form at least part of an electrical path between the arcuate contact region and its respective side of the semiconductor junction.
2. The optical device of claim 1 , wherein the resonator element comprises a first portion supportive of a microdisk optical mode and a second portion supportive of a micro-ridge optical mode.
3. The optical device of claim 2 , wherein the resonator element further comprises an adiabatic transition region between said first and second portions.
4. The optical device of claim 3 , wherein the first portion stands in relief above a substrate layer that underlies the pedestal, the second portion stands in relief above the pedestal, a pair of edges of the pedestal meet the resonator element at points of tangency that demarcate the first portion from the second portion, and the transition region lies near said points of tangency.
5. The optical device of claim 1 , wherein the pedestal is of less thickness than a resonant wavelength of light.
6. The optical device of claim 5 , wherein an electric heater is incorporated in a central portion of the resonant element.