OPTICAL CIRCUIT APPARATUS, METHOD, AND APPLICATION

• US 20120045163A1
• Filed: 08/19/2011
• Published: 02/23/2012
• Est. Priority Date: 08/20/2010
• Status: Active Grant

• Current Assignee: University of Rochester
• Original Assignee: University of Rochester
• Inventors: Wu, Hui, Wang, Shang
• Granted Patent: US 9,753,349 B2
• Time in Patent Office: Days
• US Class Current: 385/2
• CPC Class Codes: G02F 1/225 in an optical waveguide structure
• CPC Class Codes: G02F 2203/15 involving resonance effects, e.g. resonantly enhanced interaction
• CPC Class Codes: G02F 2203/585 Add/drop devices

Abstract

A new photonic integrated circuit in the form of an optical pulse-train generator utilizes a time-interleaved architecture. The circuit can generate multiple optical pulses sequentially from a single trigger pulse, with the timing and amplitude of each pulse determined by circuit design. The circuit has application in optical arbitrary waveform generation and ultrafast electro-optic modulation.

Claims

1. A time-interleaved photonic apparatus, comprising:

an input optical waveguide;

a plurality of coupler stages disposed in series along the input optical waveguide, wherein each coupler stage is characterized by a coupling coefficient that can be adjusted to determine an amplitude of an output optical pulse from each coupler stage;

a plurality of optical time-delay stages each one of which is disposed intermediate each adjacent pair of coupler stages, wherein each of the time-delay stages is characterized by an adjustable time delay;

an output component optically coupled to the plurality of coupler stages that optically combines the output pulses of the plurality of coupler stages,

wherein a customized output waveform will be created from a plurality of time-interleaved optical signals outputted from the plurality of coupler stages and outputted from the output component.

2. The apparatus of claim 1, wherein the output component is an output combiner.

3. The apparatus of claim 1, wherein the output component is an optical waveguide.

4. The apparatus of claim 1, wherein each coupler stage is at least one optical microring resonator.

5. The apparatus of claim 4, wherein the at least one optical microring resonator is an electro-optic modulator.

6. The apparatus of claim 5, further comprising a digital data bus coupled to the at least one of the electro-optic modulators,

wherein digital data to be transmitted can directly modulate each microring modulator to generate a modulated, customized output pulse train waveform.

7. The apparatus of claim 1, wherein the output combiner is one of a Y-junction and a multimode interference coupler.

8. The apparatus of claim 4, wherein the optical waveguides and the at least one optical microring resonator are silicon and are built on a silicon on insulator (SOI) platform.

9. The apparatus of claim 4, wherein the at least one optical microring resonator has a racetrack configuration.

10. The apparatus of claim 4, wherein the at least one optical microring resonator has a square configuration.

11. The apparatus of claim 4, wherein the at least one optical microring resonator has a rectangular configuration.

12. The apparatus of claim 4, wherein the plurality of optical microring resonators have a same resonant frequency.

13. The apparatus of claim 1, wherein the coupling coefficients have been adjusted to provide equal power coupling of the input optical pulse into each respective coupler stage.

14. The apparatus of claim 4, wherein each coupler stage has a different gap distance from the input optical waveguide.

15. A time domain method for generating an optical arbitrary waveform, comprising:

providing a single optical trigger pulse;

applying a plurality of sequential time delays to the single optical trigger pulse to provide a plurality, M, of sequentially time-delayed trigger input pulses;

coupling each of the sequentially time delayed trigger input pulses into each of a respective plurality M of coupler-optical resonator stages each having a coupling coefficient, to produce an output sub-pulse from each respective coupler-optical resonator stage;

adjusting the timing of each of the M output sub-pulses via the sequential time delays;

adjusting an amplitude of each of the M output sub-pulses via the coupling coefficients; and

combining the M time-delayed, amplitude-adjusted output sub-pulses to form an output optical pulse train in the form of the optical arbitrary waveform from the single optical trigger pulse.

16. The method of claim 15, wherein each of a respective plurality M of coupler-optical resonator stages consists of at least one optical microring resonator.

17. The method of claim 15, further comprising modulating the single optical trigger pulse and generating a modulated output optical pulse train in the form of the optical arbitrary waveform from the single optical trigger pulse.

18. The method of claim 15, further comprising coupling equal amplitude, time-delayed trigger input pulses into the coupler-optical resonator stages.

19. The method of claim 15, further comprising detuning a center wavelength of the single optical trigger pulse from a resonance peak of each of the coupler-optical resonator stages.

20. The method of claim 15, further comprising providing a broadband input trigger signal whose bandwidth covers all of the M channels.

21. The method of claim 20, further comprising coupling each of the sequentially time delayed trigger input pulses into each of the respective plurality M of coupler-optical resonator stages each having a different resonant frequency.