Carrier sweep-out in a tunable laser
In a first embodiment, an external cavity tunable laser, comprising a silicon photonics circuit comprising one or more resonators having one or more p-i-n junctions; wherein a voltage is applied to one or more of the p-i-n junctions. In a second embodiment, a method of operating an external cavity tunable laser, comprising sweeping out free-carriers from a resonator of the tunable laser by applying a voltage to a p-i-n junction of a waveguide of the resonator.
1. An external cavity tunable laser, comprising:
a silicon photonics circuit comprising one or more ring resonators having one or more p-i-n junctions; wherein a voltage is applied to one or more of the p-i-n junctions; wherein a reverse junction current is used to control power of the external cavity tunable laser using a control loop; wherein the reverse junction current serves as a feedback signal to enable the control loop to lock at least a ring resonator of the one or more ring resonators at a lasing wavelength.
2. The external cavity tunable laser of claim 1 , wherein the p-i-n junction is reverse biased.
3. The external cavity tunable laser of claim 1 , wherein the resonator includes a slab waveguide.
4. The external cavity tunable laser of claim 1 , wherein a first resonator of the one or more ring resonators is a first ring resonator, and wherein the silicon photonics circuit further comprises a second ring resonator; wherein a second control loop controls a voltage applied to a p-i-n junction of the second ring resonator.
5. The external cavity tunable laser of claim 1 , further comprising a gain chip coupled to the silicon photonics circuit.
6. The external cavity tunable laser of claim 5 , wherein the control loop provides feedback for the gain chip.
7. The external cavity tunable laser of claim 1 wherein the control loop is used to control a Thermo-optical phase shifter.
8. The external cavity tunable laser of claim 1 , wherein the control loop provides feedback for the cavity of the laser.
9. A method of operating an external cavity tunable laser, comprising:
sweeping out free-carriers from a ring resonator of the tunable laser by applying a voltage to a p-i-n junction of a waveguide of the ring resonator; and
using a reverse junction current as an input to a control loop to control power of the external cavity tunable laser; wherein the reverse junction current serves as a feedback signal to enable the control loop to lock at least a ring resonator of the one or more ring resonators at a lasing wavelength.
10. The method claim 9 , wherein the voltage is a reverse biasing the p-i-n junction of the waveguide of the ring resonator.
11. The method of claim 9 wherein the control loop controls a thermoelectric phase shifter.
12. The method of claim 9 wherein the control loop provides feedback for the cavity of the laser.
13. A system comprising:
an external cavity tunable laser; and
a silicon photonics circuit comprising one or more ring resonators having one or more p-i-n junctions; wherein a voltage is applied to one or more of the p-i-n junctions; using a reverse junction current to control power of the external cavity tunable laser using a control loop; wherein the control loop stabilizes laser temperature; wherein the reverse junction current serves as a feedback signal to enable the control loop to lock at least a ring resonator of the one or more ring resonators at a lasing wavelength.
14. The system of claim 13 , wherein the p-i-n junction is reverse biased.
15. The system of claim 13 , wherein a first resonator of the one or more resonators is a first ring resonator, and wherein the silicon photonics circuit further comprises a second resonator; wherein a second control loop controls a voltage applied to a p-i-n junction of the second ring resonator.