Fast tunable integrated laser

1. An apparatus comprising:

a wavelength-tunable laser; and

an electronic controller configured to control the wavelength-tunable laser such that an output wavelength of the wavelength-tunable laser performs a zigzag in time, wherein the wavelength-tunable laser comprises:

a first tunable filter apparatus; and

a second tunable filter apparatus; and

wherein the electronic controller is configured to wavelength-tune the second tunable filter apparatus at a rate, at least, five times slower than the electronic controller is configured to wavelength-tune the first tunable filter apparatus.

2. The apparatus of claim 1 , wherein the wavelength-tunable laser is an integrated device comprising:

an optical amplifier; and

a waveguide laser cavity including the optical amplifier, the waveguide laser cavity including the first tunable filter apparatus and the second tunable filter apparatus in a sequential arrangement.

3. The apparatus of claim 2 , wherein the optical amplifier is a reflective semiconductor optical amplifier and wherein the waveguide laser cavity is a silicon waveguide laser cavity.

4. The apparatus of claim 3 , wherein the first tunable filter apparatus includes one or more tunable Mach-Zehnder interferometers and the second tunable filter apparatus includes one or more tunable optical ring resonators.

5. The apparatus of claim 4 , wherein the one or more tunable Mach-Zehnder interferometers are semiconductor junction devices.

6. The apparatus of claim 4 , further comprising a heater element configured to control tuning via thermo-optic effect of the one or more tunable optical ring resonators.

7. The apparatus of claim 4 , wherein the one or more tunable Mach-Zehnder interferometers and the one or more tunable optical ring resonators are configured to perform, in combination, filtering to select a lasing mode for the wavelength-tunable laser.

8. The apparatus of claim 1 , wherein the electronic controller is further configured to generate a single monotonic wavelength sweep of the output wavelengths from the values of the monotonic wavelength sweeps.

9. An apparatus comprising:

a wavelength-tunable laser; and

an electronic controller configured to control the wavelength-tunable laser such that an output wavelength of the wavelength-tunable laser performs a zigzag in time, wherein:

the zigzag in time includes a sequence of monotonic wavelength sweeps in time, each of the monotonic wavelength sweeps comprising a respective sequence of values of the output wavelength of the wavelength-tunable laser, the values of different ones of the monotonic wavelength sweeps being interleaved.

10. The apparatus of claim 9 , wherein the electronic controller is further configured to generate a single monotonic wavelength sweep of the output wavelengths from the values of the monotonic wavelength sweeps.

11. The apparatus of claim 9 , wherein the wavelength-tunable laser comprises:

a first tunable filter apparatus; and

a second tunable filter apparatus; and

wherein the electronic controller is configured to wavelength-tune the second tunable filter apparatus at a rate, at least, five times slower than the electronic controller is configured to wavelength-tune the first tunable filter apparatus.

12. The apparatus of claim 9 , further comprising a directional LIDAR device comprising an optical transmitter and an optical receiver, the optical transmitter including the wavelength-tunable laser and the electronic controller.

13. The apparatus of claim 9 , further comprising an optical coherence tomography imaging apparatus comprising the wavelength-tunable laser and the electronic controller.

14. An apparatus comprising:

a wavelength-tunable laser; and

an electronic controller configured to control the wavelength-tunable laser such that an output wavelength of the wavelength-tunable laser performs a zigzag in time, wherein:

the zigzag in time includes a sequence of wavelength sweeps in time in which wavelengths are scanned out of order in each of the wavelength sweeps, each of the wavelength sweeps comprising a respective set of values of the output wavelength of the wavelength-tunable laser, the values of different ones of the wavelength sweeps being interleaved.

15. The apparatus of claim 14 , wherein the wavelength-tunable laser comprises:

a first tunable filter apparatus; and

a second tunable filter apparatus; and

wherein the electronic controller is configured to wavelength-tune the second tunable filter apparatus at a rate, at least, five times slower than the electronic controller is configured to wavelength-tune the first tunable filter apparatus.

16. The apparatus of claim 14 , wherein the electronic controller is further configured to generate a single monotonic wavelength sweep of the output wavelengths from the values of the monotonic wavelength sweeps.

17. The apparatus of claim 14 , further comprising a directional LIDAR device comprising an optical transmitter and an optical receiver, the optical transmitter including the wavelength-tunable laser and the electronic controller.

18. The apparatus of claim 14 , further comprising an optical coherence tomography imaging apparatus comprising the wavelength-tunable laser and the electronic controller.

19. An apparatus comprising:

a wavelength-tunable laser; and

an electronic controller configured to control the wavelength-tunable laser such that an output wavelength of the wavelength-tunable laser performs a zigzag in time, further comprising a directional LIDAR device comprising an optical transmitter and an optical receiver, the optical transmitter including the wavelength-tunable laser and the electronic controller.

20. The apparatus of claim 19 , wherein the wavelength-tunable laser comprises:

a first tunable filter apparatus; and

a second tunable filter apparatus; and

wherein the electronic controller is configured to wavelength-tune the second tunable filter apparatus at a rate, at least, five times slower than the electronic controller is configured to wavelength-tune the first tunable filter apparatus.

21. The apparatus of claim 19 , wherein the electronic controller is further configured to generate a single monotonic wavelength sweep of the output wavelengths from the values of the monotonic wavelength sweeps.

22. An apparatus comprising:

a wavelength-tunable laser; and

an electronic controller configured to control the wavelength-tunable laser such that an output wavelength of the wavelength-tunable laser performs a zigzag in time, further comprising an optical coherence tomography imaging apparatus comprising the wavelength-tunable laser and the electronic controller.

23. The apparatus of claim 22 , wherein the wavelength-tunable laser comprises:

a first tunable filter apparatus; and

a second tunable filter apparatus; and

wherein the electronic controller is configured to wavelength-tune the second tunable filter apparatus at a rate, at least, five times slower than the electronic controller is configured to wavelength-tune the first tunable filter apparatus.

24. The apparatus of claim 22 , wherein the electronic controller is further configured to generate a single monotonic wavelength sweep of the output wavelengths from the values of the monotonic wavelength sweeps.