Resonant coupling of optical signals for out-of-plane transmission that includes output beam modification
View Patent ↗An optical structure is formed on a surface of the optically resonant system to modify a characteristic of the emitted resonant signal. The optical structure may be configured to impart a phase-shift on a portion of the resonant signal. Because the resonant signal consists of a single resonant mode with an axially symmetric radiation pattern, a phase-shift can be used to, for example, collimate, disperse, direct, and generally shape output characteristics of the emitted resonant signal. The optical structure can also be used to tune the quality factor (Q) of the optically resonant system.
1. A system for redirecting an optical signal, said system comprising:
a substrate having first and second surfaces that are substantially parallel to a plane;
an optically resonant system formed in the substrate and configured to capture at least a portion of a first optical signal propagating substantially parallel to the plane and to emit a resonant signal in an out-of-plane direction relative to the substrate; and
an optical structure, formed on a surface of the optically resonant system, which is configured to modify a characteristic of the emitted resonant signal.
2. The system of claim 1 wherein the optical structure comprises a concentric ring structure.
3. The system of claim 1 wherein the optical structure comprises a plurality of concentric ring structures.
4. The system of claim 1 wherein the optical structure is a dielectric structure that is lithographically fabricated on a surface of the optically resonant system to impart a phase-shift on the emitted resonant signal.
5. The system of claim 1 wherein the optical structure is configured to phase-shift a portion of the emitted resonant signal.
6. The system of claim 1 wherein the optically resonant system includes a first structure and a second structure:
the first structure residing substantially parallel to the plane and reflecting optical radiation in a first direction substantially orthogonal to said plane; and
the second structure overlapping, and optically communicating with said first structure, and reflecting optical radiation in a direction substantially parallel to said plane;
wherein said first and second structures operate to capture at least a portion of a first optical signal propagating substantially parallel to said plane by exciting a resonant signal in a resonant cavity through resonant characteristics of said first and second structures, and further operate to emit said resonant signal in a second direction substantially orthogonal to said plane.
7. The system of claim 6 wherein the optical structure comprises a plurality of concentric ring structures.
8. The system of claim 7 wherein the concentric ring structures are configured as a function of the second structure.
9. The system of claim 7 wherein the second structure includes concentric cylinder structures and wherein the concentric ring structures are configured as a function of the concentric cylinder structures.
10. The system of claim 9 wherein the concentric ring structures are formed over annular regions of common polarity, where the annular regions are regions between the concentric cylinder structures.
11. The system of claim 1 wherein the optical structure is configured as a function of structures that form the optically resonant system.
12. The system of claim 1 wherein the optical structure has a thickness that is a function of the wavelength of the emitted resonant signal.
13. A system for redirecting an optical signal, the system comprising:
a substrate having first and second surfaces that are substantially parallel to a plane;
an optically resonant system formed in the substrate and configured to form a resonant cavity, the resonant cavity being operative to receive a first optical signal, the first optical signal exhibiting a directional component that is substantially parallel to the plane, the resonant cavity resonating in response to the first optical signal to excite and emit a resonant signal, the resonant signal being emitted in an out-of-plane direction relative to the substrate; and
an optical structure, formed on a surface of the optically resonant system, which is configured to modify a characteristic of the emitted resonant signal.
14. The system of claim 13 wherein the optical structure comprises a plurality of concentric ring structures.
15. The system of claim 13 wherein the optical structure is configured to phase-shift a portion of the emitted resonant signal.
16. The system of claim 13 wherein the resonant cavity is bounded by a first structure residing substantially in a plane and reflecting optical radiation in a first direction substantially orthogonal to the plane and a second structure optically communicating with the first structure and reflecting optical radiation in a direction substantially parallel to the plane.
17. The system of claim 16 wherein the optical structure comprises a plurality of concentric ring structures that are configured as a function of the second structure.
18. A method for redirecting optical radiation, the method comprising:
receiving a first optical signal in an optical system having first and second surfaces that are substantially parallel to a plane, the first optical signal having a directional component that is substantially parallel to the plane and including at least one wavelength;
exciting a resonant signal in response to the first optical signal at the at least one wavelength;
emitting the resonant signal in an out-of-plane direction relative to the substrate; and
phase-shifting a portion of the resonant signal that is emitted in the out-of-plane direction to modify a characteristic of the resonant signal.
19. The method of claim 18 further comprising passing the resonant signal through an optical structure that is formed as a function of the wavelength of the resonant signal.
20. The method of claim 18 further comprising phase-shifting portions of the resonant signal at regions of common polarity.