Super-ring resonator based devices
View Patent ↗This invention provides an optical device comprising a large group of non-uniform resonators operating cumulatively as a ‘super-ring’ to provide a controllable group delay with large bandwidth. The super-ring tuning is performed by a single control. The device may include two super-rings, each includes a large number of resonators with a resonant frequencies centered around ω 1 and ω 2 respectively. The invention provides multiple ways to improve the delay duration, bandwidth and the tuning speed, and overcomes the issue of non-uniformity of resonance frequency for devices incorporating multiple optical resonators.
1. An optical device, comprising: M loop resonators made with a first distribution of resonant frequencies around a central frequency ω 1 (M≧2), M loop resonators form a first super-ring; the optical device receiving incoming light and outputting modified light, wherein the output light characteristics are determined by the first super-ring characteristics, which are different from characteristics of a single loop resonator, further comprising: M loop resonators made with a second distribution of resonant frequencies around a central frequency ω 2 forming a second super-ring, (M≧2); the device outputting the signal, which is a time delayed version of the input signal (provided by a constant group delay of all wavelengths in the signal), wherein an output light signal is determined by both super-ring characteristics, which are different from characteristics of each single super-ring at ω 1 and ω 2 , wherein the second super-ring contains the same M number of rings as the first super-ring thus providing the same group delay characteristic as the first super-ring, but with the opposite sign of the group delay dispersion on the signal which is centered between ω 1 and ω 2 .
2. The optical device of claim 1 , wherein the first distribution is Gaussian with a given mean square deviation Aω 1 .
3. The optical device of claim 2 , wherein Δω≧0.02 ω 1 .
4. The optical device of claim 1 , wherein the light is an electromagnetic wave with a frequency ranging from UV to infrared.
5. The optical device of claim 1 operating as a tunable filter; the device outputting a signal that is a filtered version of the input signal.
6. The optical device of claim 1 operating as a tunable dispersion compensator; the device outputting a signal modified by the addition of dispersion by the compensator.
7. The optical device of claim 1 operating to provide a tunable phase delay or a tunable group delay, with much broader bandwidth than a single loop resonator can provide.
8. The optical device of claim 7 , wherein a peak delay of the first super-ring is larger than a peak delay of a single resonator.
9. The optical device of claim 1 , wherein the first super-ring is tuned with a single control.
10. The optical device of claim 9 , wherein the single control is a single temperature, a single voltage or a single current to control the central frequency of the full first super-ring response.
11. The optical device of claim 1 , wherein the first distribution shape is specifically designed distribution.
12. The optical device of claim 1 , wherein the loop resonator may be any form of optical resonator structure, tunable resonator or filter, including micro-ring resonators, Bragg gratings, photonic crystals, free space resonators, both 2D and 3D.
13. The optical device of claim 1 , wherein an output signal bandwidth is wider than a bandwidth of a single loop resonator and wider than a bandwidth of a delay consisting of two resonators with ω 1 and ω 2 resonator frequencies.
14. The optical device of claim 1 , wherein a peak delay is larger than a peak delay of a single resonator.
15. The optical device of claim 1 , wherein the delay is tunable.
16. The optical device of claim 15 , wherein the tuning is performed by simultaneous tuning up and down the first and second super-rings using a first and a second single controls applied to each super-ring respectively.
17. The optical device of claim 15 , wherein the resonant angular frequencies ω 1 and ω 2 are tunable within a range of +/−0.1% within 10 microseconds.
18. The optical device of claim 15 , wherein the tuning is performed by a balanced thermal approach, which includes simultaneous thermal tuning up and down the first and second super-rings respectively.
19. The optical device of claim 1 , wherein the difference in resonant frequencies of the resonators within each super-ring is up to 2%.
20. The optical device of claim 1 , wherein the incoming optical signal is an RF modulated optical carrier including a single frequency carrier and a single signal side band, and the device is providing a phase delay for the carrier and a group delay for the side band.
21. The optical device of claim 20 , wherein the group delay is up to 10 ns.
22. The optical device of claim 1 , wherein the central resonant angular frequencies ω 1 =ω 0 +Δω and ω 2 =ω 0 −Δω of the loop resonators being equally distant from a frequency ω 0 , wherein ω 0 is an input signal median frequency.