Method and system for an optoelectronic built-in self-test system for silicon photonics optical transceivers
View Patent ↗Methods and systems for an optoelectronic built-in self-test (BIST) system for silicon photonics optical transceivers are disclosed and may include, in an optoelectronic transceiver having a transmit (Tx) path and a receive (Rx) path, where the Rx path includes a main Rx path and a BIST loopback path: generating a pseudo-random bit sequence (PRBS) signal, generating an optical signal in the Tx path by applying the PRBS signal to a modulator, communicating the optical signal to the BIST loopback path and converting to an electrical signal utilizing a photodetector, the photodetector being a replica of a photodetector in the main Rx path, and assessing the performance of the Tx and Rx paths by extracting a PRBS signal from the electrical signal. The transceiver may be a single complementary-metal oxide semiconductor (CMOS) die or in two CMOS die, where a first comprises electronic devices and a second comprises optical devices.
1. A method for optical communication, the method comprising:
in an optoelectronic transceiver on an optoelectronics die and one or more electronics die, the transceiver having a transmit (Tx) path and a receive (Rx) path, the Rx path comprising a main Rx path and a built-in self-test loopback path:
generating a pseudo-random bit sequence (PRBS) signal in at least one of the one or more electronics die;
multiplexing the PRBS signal with an input electrical signal;
generating an optical signal in the Tx path by applying the multiplexed input electrical signal and PRBS signal to an optical modulator in the optoelectronics die;
communicating the optical signal to a portion of the built-in self-test loopback path in the optoelectronics die;
converting the optical signal to an electrical signal in the Rx path utilizing a loopback photodetector in the built-in self-test loopback path, the loopback photodetector being a replica of a photodetector in the main Rx path;
extracting, in the electronics die, the PRBS signal and the input electrical signal from the electrical signal; and
assessing performance of the Tx and Rx paths by reducing an input power of the optical signal in the Tx path while monitoring a bit error rate.
2. The method according to claim 1 , wherein the optoelectronics die comprises a silicon photonic interposer.
3. The method according to claim 1 , wherein the one or more electronics die comprises one or more complementary-metal oxide semiconductor (CMOS) die.
4. The method according to claim 1 , wherein the one or more electronics die is bonded directly to the optoelectronics die.
5. The method according to claim 4 , wherein the one or more electronics die is coupled to the optoelectronics die using copper pillars.
6. The method according to claim 1 , wherein the optical modulator comprises a Mach-Zehnder Interferometer.
7. The method according to claim 1 , wherein a transimpedance amplifier coupled to an output of the loopback photodetector in the self-test loopback path is a replica of a transimpedance amplifier coupled to an output of a photodetector in the main Rx path.
8. The method according to claim 1 , comprising extracting the PRBS signal and the input electrical signal from the electrical signal utilizing a demultiplexer in the Rx path.
9. The method according to claim 1 , comprising receiving a second optical signal in the main Rx path.
10. The method according to claim 9 , comprising generating a second electrical signal from the received second optical signal utilizing the photodetector in the main Rx path.
11. The method according to claim 10 , comprising multiplexing the electrical signal in the Rx path with the second electrical signal.
12. A system for communication, the system comprising:
an optoelectronic transceiver on an optoelectronics die and one or more electronics die, the transceiver having a transmit (Tx) path and a receive (Rx) path, the Rx path comprising a main Rx path and a built-in self-test loopback path, the optoelectronic transceiver being operable to:
generate a pseudo-random bit sequence (PRBS) signal in at least one of the one or more electronics die;
multiplexing the PRBS signal with an input electrical signal;
generate an optical signal in the Tx path by applying the multiplexed PRBS signal and input electrical signal to an optical modulator in the optoelectronics die;
communicate the optical signal to the built-in self-test loopback path in the optoelectronics die;
convert the optical signal to an electrical signal in the Rx path utilizing a loopback photodetector in the built-in self-test loopback path, the loopback photodetector being a replica of a photodetector in the main Rx path, wherein both photodetectors comprise SiGe and are integrated into the optoelectronics die; and
extract, in the electronics die, the PRBS signal and the input electrical signal from the electrical signal.
13. The system according to claim 12 , wherein the optoelectronic transceiver is in a silicon photonically-enabled integrated circuit.
14. The system according to claim 13 , wherein the silicon photonically-enabled integrated circuit is in a single complementary-metal oxide semiconductor (CMOS) die.
15. The system according to claim 13 , wherein the silicon photonically-enabled integrated circuit is in two die, a first die comprising electronic devices and a second die comprising optical devices.
16. The system according to claim 15 , wherein the two die comprise CMOS die.
17. The system according to claim 12 , wherein the optical modulator comprises a Mach-Zehnder Interferometer.
18. The system according to claim 12 , wherein a transimpedance amplifier coupled to an output of the loopback photodetector in the self-test loopback path is a replica of a transimpedance amplifier coupled to an output of a photodetector in the main Rx path.
19. The system according to claim 12 , wherein the optoelectronic transceiver is operable to extract the PRBS signal and the input electrical signal from the electrical signal utilizing a demultiplexer in the Rx path.
20. The system according to claim 12 , wherein the optoelectronic transceiver is operable to receive a second optical signal in the main Rx path.
21. The system according to claim 20 , wherein the optoelectronic transceiver is operable to generate a second electrical signal from the received second optical signal utilizing the photodetector in the main Rx path and multiplex the electrical with the second electrical signal.
22. A method for communication, the method comprising:
in an optoelectronic transceiver on an optoelectronics die and one or more electronics die, the transceiver having a transmit (Tx) path and a receive (Rx) path, the Rx path comprising a main Rx path and a built-in self-test loopback path:
generating a first electrical signal in the Tx path in at least one of the one or more electronics die;
generating a pseudo-random bit sequence (PRBS) signal in the at least one of the one or more electronics die;
multiplexing the first electrical signal with the PRBS signal in the at least one of the one or more electronics die;
generating a first optical signal in the Tx path by applying the multiplexed electrical and PRBS signals to an optical modulator in the optoelectronics die;
receiving a second optical signal in the Rx path and converting to a second electrical signal utilizing a photodetector in the main Rx path;
communicating the first optical signal to a portion of the built-in self-test loopback path in the optoelectronics die;
converting the first optical signal to a third electrical signal in the Rx path utilizing a loopback photodetector in the built-in self-test loopback path, the loopback photodetector being a replica of a photodetector in the main Rx path;
multiplexing the second and third electrical signals in the Rx path in the at least one of the one or more electronics die;
extracting, in the electronics die, the PRBS signal and the first electrical signal from the multiplexed second and third electrical signals; and
assessing performance of the Tx and Rx paths by reducing an input power of the optical signal in the Tx path while monitoring a bit error rate.
23. A method for communication, the method comprising:
in an optoelectronic transceiver on an optoelectronics die and one or more electronics die, the transceiver having a transmit (Tx) path and a receive (Rx) path:
generating a pseudo-random bit sequence (PRBS) signal in at least one of the one or more electronics die;
multiplexing the PRBS signal with an input electrical signal;
generating an optical signal in the Tx path by applying the multiplexed PRBS signal and input electrical signal to an optical modulator in the optoelectronics die;
communicating the optical signal to a portion of the Rx path in the optoelectronics die;
converting the optical signal to an electrical signal in the Rx path utilizing a photodetector in the optoelectronics die;
extracting, in the electronics die, the PRBS signal and the input electrical signal from the electrical signal; and
assessing performance of the Tx and Rx paths by reducing an input power of the optical signal in the Tx path while monitoring a bit error rate.