Ultralow noise optical clock for high speed sampling applications

• US 6,735,229 B1
• Filed: 05/22/2003
• Issued: 05/11/2004
• Est. Priority Date: 05/23/2002
• Status: Expired due to Fees

• Current Assignee: University of Central Florida (State University System of Florida)
• Original Assignee: University of Central Florida (State University System of Florida)
• Inventors: Yilmaz, Tolga, Depriest, Christopher M., Delfyett, Peter J.
• Primary Examiner(s): Scott, Jr., Leon
• Application Number:
  US10/443,495
• Time in Patent Office: 355 Days
• Field of Search: 372/38, 372/28, 372/26, 372/18
• US Class Current: 372/38.08
• CPC Class Codes: H01S 3/06791 Fibre ring lasers fibre laser gyrometers G01C19/72
• CPC Class Codes: H01S 3/08036 using intracavity dispersive, polarising or birefringent elements
• CPC Class Codes: H01S 3/1109 Active mode locking
• CPC Class Codes: H01S 3/1121 Harmonically mode locking lasers, e.g. modulation frequency equals multiple integers or a fraction of the resonator roundtrip time

Abstract

Methods and systems for using a laser type clock to produce a train of ultra-stable optical pulses. The methods and systems include generating an approximately 10 GHz ultralow noise pulse train from a harmonically modelocked laser having an intracavity Fabry-Perot etalon filter from a semiconductor lasers such as ring lasers, and the like. System output can have residual phase modulation(PM) noise values of approximately 18 fs and amplitude modulation(AM) noise values of approximately 0.05% RMS, and residual phase modulation(PM) noise values of approximately 94 fs and amplitude modulation(AM) noise values of approximately 0.05% RMS.

Claims

1. A method of producing ultralow noise and supermode suppression in a laser having a laser cavity, comprising the steps of:

modelocking the laser;

suppressing noise from the laser with an intracavity filter; and

generating ultralow noise pulse trains from the laser.

2. The method of claim 1, wherein the step of modelocking includes the step of:

harmonically modelocking an external cavity.

3. The method of claim 2, wherein the step of harmonically modelocking includes the step of:

harmonically modelocking the cavity at approximately 80 kHz.

4. The method of claim 3, wherein the semiconductor laser includes:

a semiconductor diode ring laser.

5. The method of claim 1, wherein the step of modelocking includes the step of:

modelocking a cavity with a Mach-Zehnder modulator (MZM) having an approximately 20 GHz modulation bandwidth.

6. The method of claim 1, wherein the step of modelocking the laser includes the step of:

providing a semiconductor laser as the laser.

7. The method of claim 1, wherein the step of suppressing noise includes the step of:

providing an etalon filter as the intracavity filter.

8. The method of claim 7, wherein the step of suppressing noise further includes the step of:

providing an approximately 180 finesse, approximately 10 GHz fiber-Fabry-Perot (FFP) filter as the etalon filter.

9. The method of claim 1, wherein the step of generating includes the step of:

generating an approximately 10 GHz pulse train from the laser.

10. The method of claim 1, wherein the ultra noise pulse trains include:

residual phase modulation(PM) noise values of approximately 18 fs and amplitude modulation(AM) noise values of approximately 0.05% RMS.

11. The method of claim 1, wherein the ultra noise pulse trains include:

residual phase modulation(PM) noise values of approximately 94 fs and amplitude modulation(AM) noise values of approximately 0.05% RMS.

12. A laser system for producing ultralow noise and supermode suppression, comprising:

means for modelocking a laser;

intracavity filter means for suppressing noise from the laser; and

means for generating ultralow noise pulse trains from the laser.

13. The laser system of claim 12, wherein the modelocking means includes:

means for harmonically modelocking an external cavity at approximately 80 kHz.

14. The laser system of claim 12, wherein the modelocking means includes:

means for modelocking a cavity with a Mach-Zehnder modulator (MZM) having an approximately 20 GHz modulation bandwidth.

15. The laser system of claim 12, wherein the laser includes:

a semiconductor laser.

16. The laser system of claim 12, wherein the intracavity filter means includes:

an etalon filter.

17. The laser system of claim 16, wherein the etalon filter includes:

an approximately 180 finesse, approximately 10 GHz fiber-Fabry-Perot (FFP) filter.

18. The laser system of claim 12, wherein the generating means includes:

means for producing an approximately 10 GHz pulse train from the laser.

19. The laser system of claim 12, wherein the ultra low noise pulse trains include:

residual phase modulation(PM) noise values of approximately 18 fs and amplitude modulation(AM) noise values of approximately 0.05% RMS.

20. The laser system of claim 12, wherein the ultra noise pulse trains include:

residual phase modulation(PM) noise values of approximately 94 fs and amplitude modulation(AM) noise values of approximately 0.05% RMS.