Multi-wavelength laser

1. A communication system, comprising:

a data transmission interface; and

a wavelength division multiplexing (WDM) silicon laser source to provide modulated data on a carrier laser via the data transmission interface, the WDM laser comprising a single laser cavity to generate an internally multiplexed multi-wavelength laser, the single laser cavity comprising a filter having a first grating period to generate a first wavelength and a second grating period to generate a second wavelength, the second grating period superimposed on the first grating period.

2. The communication system of claim 1 , wherein the WDM laser is a multi-wavelength distributed feedback laser.

3. The communication system of claim 1 , wherein the filter is a Bragg filter.

4. The communication system of claim 1 , wherein the filter comprises sinusoidal apodization.

5. The communication system of claim 1 , wherein the filter comprises square wave apodization.

6. The communication system of claim 1 , wherein the filter comprises a one-quarter wavelength phase shift.

7. The communication system of claim 1 , wherein the filter comprises a first phase shift for the first wavelength and a second phase shift for the second wavelength, wherein the second phase shift is spatially offset from the first phase shift.

8. The communication system of claim 1 , wherein the filter comprises means to separate peak power of the first wavelength from peak power of the second wavelength.

9. The communication system of claim 1 , further comprising third and fourth grating periods superimposed on the first grating period to generate third and fourth wavelengths respectively.

10. The communication system of claim 1 , further comprising a modulator to modulate the data onto the carrier laser.

11. The communication system of claim 10 , wherein the modulator is a ring modulator.

12. The communication system of claim 10 , wherein the modulator comprises a ring modulator per generated frequency.

13. An integrated circuit (IC), comprising:

a local data interface;

a fiberoptic transmitter circuit; and

an IC-scale laser to drive the fiberoptic transmitter circuit, the laser comprising a monolithic laser cavity comprising a filter having a first grating period and a second grating period superimposed on the first grating period;

whereby the first grating period generates a carrier of a first wavelength and the second grating period generates a carrier of a second wavelength multiplexed with the carrier of the first wavelength.

14. The IC of claim 13 , wherein the filter has a sinusoidal apodization.

15. The IC of claim 13 , wherein the filter has a square wave apodization.

16. The IC of claim 13 , wherein the filter comprises a first phase shift for the first wavelength and a second phase shift for the second wavelength, wherein the second phase shift is spatially offset from the first phase shift.

17. The IC of claim 13 , wherein the filter comprises means to separate peak power of the first wavelength from peak power of the second wavelength.

18. The IC of claim 13 , further comprising third and fourth grating periods superimposed on the first grating period to generate third and fourth wavelengths respectively.

19. A Bragg filter, comprising:

a first grating period and a second grating period superimposed on the first grating period, wherein the first grating period is configured to selectively reflect a first wavelength and the second grating period is configured to selectively reflect a second wavelength, and wherein the second grating period is superimposed over the first grating period.

20. The Bragg filter of claim 19 , wherein the first and second grating periods are provided in a square wave apodization structure.