Light source redundancy in optical communication devices

1. An optical transmitter, comprising:

a dual strip light source that includes:

a primary laser to transmit a primary continuous wave (CW) signal; and

a backup laser to transmit a backup CW signal;

a lens coupled to the dual stripe light source;

a photonic integrated circuit (PIC) that includes:

a first input port configured to receive the primary CW signal from the primary laser;

a second input port configured to receive the backup CW signal from the backup laser;

a Mach-Zehnder optical modulator (MZM) having a first input coupled to the first input port and a second input coupled the second input port and configured to modulate at least a portion of the primary CW signal or at least a portion of the backup CW signal to generate a modulated optical data signal; and

an output port configured output the modulated optical data signal from the PIC; and

an optical isolator coupled between the lens and the PIC;

wherein the optical transmitter is configured to activate the backup laser in response to determining that the primary laser has failed or is failing.

2. The optical transmitter of claim 1 , the PIC further comprising at least one sensor to sense a power level of the primary CW signal to determine whether the primary laser has failed or is failing.

3. The optical transmitter of claim 2 , wherein the at least one sensor comprises at least one photodiode.

4. The optical transmitter of claim 1 , further comprising:

a second primary laser to transmit a second primary CW signal; and

a second backup laser to transmit a second backup CW signal;

wherein the PIC further includes:

a third input port configured to receive the second primary CW signal from the second primary laser;

a fourth input port configured to receive the second backup CW signal from the second backup laser;

a second MZM coupled to both the third input port and the fourth input port and configured to modulate at least a portion of the second primary CW signal or at least a portion of the second backup CW signal to generate a second modulated optical data signal; and

a second output port configured to output the second modulated optical data signal from the PIC;

wherein the optical transmitter is configured to activate the second backup laser in response to determining that the second primary laser has failed or is failing.

5. The optical transmitter of claim 1 , wherein the optical transmitter comprises an N-channel optical transmitter, wherein N is a positive integer.

6. An optical transmitter, comprising:

a dual stripe light source that includes a first laser and a second laser; and

a photonic integrated circuit (PIC) that includes a first input port, a second input port, a Mach-Zehnder optical modulator (MZM) having first and second inputs respectively coupled to the first input port and the second input port, and an output port coupled to an output of thr MZM;

wherein:

the first input port is configured to receive a first continuous wave (CW) signal from the first laser;

the second input port is configured to receive a second CW signal from the second laser;

the MZM is configured to modulate at least a portion the first CW signal when the first laser is activated or at least a portion of the second CW signal when the second laser is activated to generate a modulated optical data signal;

the output port is configured to output the modulated optical data signal from the PIC; and

the optical transmitter is configured to:

sense an optical power level of the first CW signal; and

activate the second laser in response to the optical power level of the first CW signal being below a threshold value.

7. The optical transmitter of claim 6 , further comprising at least one sensor configured to sense the optical power level of the first CW signal.

8. The optical transmitter of claim 6 , wherein the PIC further includes:

a third input port configured to receive a third CW signal from a third laser;

a fourth input port configured to receive a fourth CW signal from a fourth laser; and

a second MZM coupled to both of the third and fourth input ports and configured to modulate at least a portion of the third CW signal when the third laser is activated or at least a portion of the fourth CW signal when the fourth laser is activated to generate a second modulated optical data signal.

9. The optical transmitter of claim 8 , wherein the optical transmitter is further configured to:

sense an optical power level of the third CW signal; and

activate the fourth laser in response to the optical power level of the third CW signal being below the threshold value.

10. The optical transmitter of claim 6 , wherein the optical transmitter is further configured to deactivate the first laser in response to the optical power level of the first CW signal being below a threshold value.

11. The optical transmitter of claim 6 , wherein the optical transmitter is configured to determine that the first laser is failing or has failed if the optical power level of the first CW signal is below the threshold value.

12. A method, comprising:

transmitting, from a first laser of a dual stripe light source, a first continuous wave (CW) signal through a lens and an optical isolator to a photonic integrated circuit (PIC);

routing at least a portion of the first CW signal within the PIC to a first input of a Mach-Zehnder optical modulator (MZM) formed in the PIC;

modulating the at least the portion of the first CW signal in the MZM to generate a modulated optical data signal;

determining whether the first laser has failed or is failing;

activating a second laser of the dual stripe light source in response to determining that the first laser has failed or is failing;

deactivating the first laser in response to determining that the first laser has failed or is failing;

transmitting, from the second laser, a second CW signal through the lens and the optical isolator to the PIC;

routing at least a portion of the second CW signal within the PIC to a second input of the MZM; and

modulating the at least the portion of the second CW signal in the MZM to generate the modulated optical data signal.

13. The method of claim 12 , wherein determining whether the first laser has failed or is failing comprises sensing a power level of the first CW signal via at least one photodiode to determine if the first laser has failed or is failing.

14. The method of claim 12 , further comprising:

transmitting, from a third laser, a third CW signal through the lens and the optical isolator to the PIC;

routing at least a portion of the third CW signal within the PIC to a second MZM formed in the PIC;

modulating the at least the portion of the third CW signal in the second MZM to generate a second modulated optical data signal;

determining whether the third laser has failed or is failing;

activating a fourth laser in response to determining that the third laser has failed or is failing;

deactivating the third laser in response to determining that the third laser has failed or is failing;

transmitting, from the fourth laser, a fourth CW signal through the lens and the optical isolator to the PIC;

routing at least a portion of the fourth CW signal within the PIC to the second MZM; and

modulating the at least the portion of the fourth CS signal in the MZM to generate the second modulated optical data signal.

15. The method of claim 14 , wherein determining whether the third laser has failed or is failing comprises sensing a power level of the third CW signal via at least one photodiode to determine if the third laser has failed or is failing.