Claims
- 1. Laser apparatus comprising
- first and second optical output ports,
- first and second fiber lasers having at least partially overlapping cavity resonators,
- said resonators including first and second grating reflectors associated with said first and second lasers, respectively, and a third reflector common to said lasers,
- said lasers capable of operating in either a phase locked state or a phase unlocked state, and
- a polarization transformer disposed in said overlapping resonators for controlling the phase state in which said lasers operate,
- the reflectivity of said common reflector and said phase state of said lasers controlling the relative optical power delivered to said ports.
- 2. The invention of claim 1 further comprising a modulator for controlling the reflectivity of said third reflector, thereby to control, in conjunction with said transformer, the relative optical power delivered to said ports.
- 3. The invention of claim 1 wherein said lasers are phase locked and said resonators have different optical lengths, thereby to reduce beat noise in said lasers.
- 4. The invention of claim 3 wherein said apparatus delivers optical power to at least one utilization device having an electrical bandwidth B.sub.e and wherein the difference .DELTA.L in said optical lengths satisfies the inequality c/10nB.sub.e .ltoreq..DELTA.L.ltoreq.9c/10nB.sub.e.
- 5. The invention of claim 1 wherein said polarization transformer comprises a polarization modulator.
- 6. The invention of claim 1 wherein said polarization transformer comprises at least a portion of the optical path of said resonators having birefringence properties.
- 7. The invention of claim 6 wherein said portion comprises PMF and the amount of birefringence in said path is related to the linewidth of said reflectors as follows: L.sub.PMF >.lambda..sup.2 /B.DELTA..lambda..sub.r, where L.sub.PMF is the length of said PMF portion, .lambda. is the lasing wavelength of said lasers, B is the birefringence of said PMF portion, and .DELTA..lambda..sub.r is the portion of the overlapping bandwidth of said reflectors common to all three of said reflectors.
- 8. The invention of claim 7 wherein said portion comprises first and second segments of PMF joined to one another so that at the joint their principal axes are at essentially 45 degrees to one another.
- 9. The invention of claim 8 wherein said first segment is approximately twice as long as said second segment.
- 10. Laser apparatus comprising
- first and second high reflectivity grating reflectors and a common grating reflector forming a complex cavity resonator,
- an optical fiber coupler disposed within said resonator, said coupler having at least four ports,
- first and second fiber active media disposed within said resonator so as to form first and second lasers with at least partially overlapping resonators within said complex resonator,
- said first reflector and said first active medium being coupled to a first one of said ports, said second reflector and said second active medium being coupled to a second one of said ports, said common reflector being coupled to a third one of said ports, and optical outputs being coupled from said third port and from a fourth one of said ports,
- said lasers being operable in a phase locked state and a phase unlocked state, and
- an intracavity polarization transformer for controlling said phase state in which said lasers operate, the reflectivity of said common reflector and said phase state of said lasers controlling the relative optical power delivered as said optical outputs via said third and fourth ports.
- 11. The invention of claim 10 wherein said lasers are phase locked and said overlapping resonators have sufficiently different optical lengths to reduce beat noise in said lasers.
- 12. The invention of claim 11 wherein said apparatus delivers optical power to at least one utilization device having an electrical bandwidth B.sub.e and wherein the difference .DELTA.L in said optical lengths satisfies the inequality c/10nB.sub.e .ltoreq..DELTA.L.ltoreq.9c/10nB.sub.e.
- 13. Laser apparatus comprising
- an optical output port,
- first and second fiber lasers having at least partially overlapping cavity resonators,
- said resonators including first and second grating reflectors associated with said first and second lasers, respectively, and a third reflector common to said lasers,
- said lasers capable of operating in either a phase locked state or a phase unlocked state, and
- a polarization transformer disposed in said overlapping resonators for controlling the phase state in which said lasers operate,
- the reflectivity of said common reflector and said phase state of said lasers controlling the amount of optical power delivered to said port.
- 14. The invention of claim 13 further comprising a modulator for controlling the reflectivity of said third reflector, thereby to control, in conjunction with said transformer, the amount of optical power delivered to said port.
- 15. The invention of claim 13 wherein said lasers are phase locked and said resonators have different optical lengths, thereby to reduce beat noise in said lasers.
- 16. The invention of claim 15 wherein said apparatus delivers optical power to at least one utilization device having an electrical bandwidth B.sub.e and wherein the difference .DELTA.L in said optical lengths satisfies the inequality c/10nB.sub.e .ltoreq..DELTA.L.ltoreq.9c/10nB.sub.e.
- 17. The invention of claim 13 wherein said polarization transformer comprises a polarization modulator.
- 18. The invention of claim 13 wherein said polarization transformer comprises at least a portion of the optical path of said resonators having birefringence properties.
- 19. The invention of claim 18 wherein said portion comprises PMF and the amount of birefringence in said path is related to the linewidth of said reflectors as follows: L.sub.PMF >.lambda..sup.2 /B.DELTA..lambda..sub.r, where L.sub.PMF is the length of said PMF portion, .lambda. is the lasing wavelength of said lasers, B is the birefringence of said PMF portion, and .DELTA..lambda..sub.r is the portion of the overlapping bandwidth of said reflectors common to all three of said reflectors.
- 20. The invention of claim 19 wherein said portion comprises first and second segments of PMF joined to one another so that at the joint their principal axes are at essentially 45 degrees to one another.
- 21. The invention of claim 20 wherein said first segment is approximately twice as long as said second segment.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 08/910,948 filed on Aug. 8, 1997 and entitled "Multiple Fiber Laser Pump Sources" (Grubb 10-13-56) which claims priority from a provisional application Ser. No. 60/026,906 filed on Sep. 26, 1996.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
723323 A2 |
Jul 1996 |
EPX |
Continuation in Parts (1)
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Number |
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910948 |
Aug 1997 |
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