Monolithically integrated system on chip for silicon photonics
A hybrid electrical and optic system-on-chip (SOC) device configured for both electrical and optic communication includes a substrate, an electrical device configured for electrical communication arranged on the substrate, a photonics device configured for optic communication arranged on the substrate, and a self-test module arranged on the substrate. The self-test module is configured to receive a loop-back signal indicative of an optical signal output from the photonics device and calibrate the photonics device based on the loop-back signal.
1. A hybrid electrical and optic system-on-chip (SOC) device configured for both electrical and optic communication, the SOC device comprising:
a substrate;
electrical communication circuitry disposed on the substrate, the electrical communication circuitry configured to send and receive electrical communication signals over an electrical communications link;
a photonics communication device disposed on the substrate, the photonics communication device configured to send and receive optical communication signals over an optical communications link; and
photonics control circuitry disposed on the substrate, the photonics control circuitry configured to (i) receive, from the photonics communication device, a feedback signal indicative of an optical signal received by or output from the photonics communication device and (ii) control an operation of the photonics communication device based on the feedback signal.
2. The SOC device of claim 1 , the photonics control circuitry comprising a light source configured to emit light that is received by the photonics communication device, wherein the feedback signal is indicative of the light emitted by the light source of the photonics control circuitry.
3. The SOC device of claim 2 , the light source comprising a broadband source configured to emit electromagnetic radiation in a range from 1200 to 1600 nm.
4. The SOC device of claim 2 , the light source comprising a light emitting diode.
5. The SOC device of claim 1 , further comprising a first optical coupler coupled to a transmit path of the optical signal and configured to (i) receive the optical signal and (ii) provide the feedback signal from the transmit path to a second optical coupler coupled to a receive path, the photonics control circuitry being configured to receive the feedback signal via the receive path.
6. The SOC device of claim 5 , further comprising an isolation switch coupled between the transmit path and the receive path, the isolation switch being configured to prevent crosstalk between the transmit path and the receive path.
7. The SOC device of claim 1 , further comprising a transmit multiplexer and a receive multiplexer, the photonics control circuitry configured to output a light signal to the transmit multiplexer and receive the feedback signal from the receive multiplexer.
8. The SOC device of claim 1 , the photonics control circuitry further comprising a self-test output configured to output a self-test signal indicating a change in the optical signal.
9. The SOC device of claim 1 , the photonics control circuitry configured to tune the photonics communication device responsive to the feedback signal.
10. The SOC device of claim 9 , the photonics control circuitry being configured to tune at least one of a laser bias and a modulator bias of the photonics communication device.
11. The SOC device of claim 9 , the photonics control circuitry being configured to control at least one of thermal tuning and carrier tuning of the photonics communication device.
12. The SOC device of claim 1 , further comprising:
an electrical interface coupled to the electrical communication circuitry;
a first transmit path configured to receive electrical data from the photonics communication device and transmit electrical data from the SOC device over the electrical interface; and
a first receive path configured to receive electrical data over the electrical interface.
13. The SOC device of claim 12 , further comprising:
an optical interface coupled to the photonics communication device;
a second transmit path configured to convert electrical data received from the electrical communication circuitry to optical data and transmit optical data from the SOC device over the optical interface; and
a second receive path configured to convert optical data received over the optical interface to electrical data and provide electrical data converted from optical data to the electrical communication circuitry.
14. A method of operating a hybrid electrical and optic system-on-chip (SOC) device configured for both electrical and optic communication, the method comprising:
using electrical communication circuitry disposed on a substrate, (i) receiving electrical data from a photonics communication device disposed on the substrate and transmitting electrical data from the SOC device over an electrical interface and (ii) receiving electrical data over the electrical interface;
using the photonics communication device, (i) converting electrical data received from the electrical communication circuitry to optical data and transmitting optical data from the SOC device over an optical interface and (ii) converting optical data received over the optical interface to electrical data and providing electrical data converted from optical data to the electrical communication circuitry;
receiving a feedback signal indicative of an optical signal received by or output from the photonics communication device; and
controlling an operation of the photonics communication device based on the feedback signal.
15. The method of claim 14 , further comprising emitting light from a light source disposed on the substrate, receiving the light using the photonics communication device, and generating the feedback signal based on the light emitted by the light source.
16. The method claim 14 , further comprising generating the feedback signal using a first optical coupler coupled to a transmit path of the photonics communication device.
17. The method of claim 16 , further comprising providing the feedback signal to a receive path using a second optical coupler.
18. The method of claim 17 , further comprising arranging an isolation switch between the transmit path and the receive path to prevent crosstalk between the transmit path and the receive path.
19. The SOC device of claim 1 , further comprising transimpedance amplifier (TIA) circuitry disposed in a path between the photonics communication device and the electrical communication circuitry, the TIA circuitry configured to convert signals from a photo diode detector into a voltage signal for processing by the electrical communication circuitry.