Optical pulse amplifier and optical pulse source

• US 8,275,010 B2
• Filed: 06/10/2008
• Issued: 09/25/2012
• Est. Priority Date: 06/28/2007
• Status: Active Grant

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: Oguri, Atsushi, Matsushita, Shunichi
• Primary Examiner(s): Rodriguez, Armando
• Assistant Examiner(s): FORDE, DELMA ROSA
• Application Number:
  US12/136,533
• Publication Number:
  US 20090003394A1
• Time in Patent Office: 1,568 Days
• Field of Search: 372/25, 372/6, 359/337.5, 359/341.1, 359/333, 398/80, 398/81, 398/87, 398/193, 398/199, 398173-181, 398/146, 398/160, 385/14, 385/15, 385/31, 385/88, 385/89, 385/92, 385/94, 385/122
• US Class Current: 372/25
• CPC Class Codes: H01S 3/0057 Temporal shaping, e.g. pulse compression, frequency chirping soliton generation and propagation G02F1/3513, H01S3/063 and H01S3/108
• CPC Class Codes: H01S 3/06704 Housings; Packages
• CPC Class Codes: H01S 3/06725 Fibre characterized by a specific dispersion, e.g. for pulse shaping in soliton lasers or for dispersion compensating [DCF]
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/06779 with optical power limiting
• CPC Class Codes: H01S 3/2316 Cascaded amplifiers

Abstract

The pulse light source according to the present invention comprises: a seed pulse generator 1 for outputting an input pulse 10 as a seed pulse; a pulse amplifier 2; and a dispersion compensator 3 for dispersion compensating a light pulse output from the pulse amplifier 2. Moreover, the pulse amplifier 2 comprises a normal dispersion medium (DCF 4) and an amplification medium (EDF 5) that are multistage-connected alternately, for changing the input pulse 10 to a light pulse having a linear chirp and outputting the light pulse. Furthermore, an absolute value of the dispersion of the DCF 4 becomes to be larger than the absolute value of the dispersion of the EDF 5.

Claims

1. A pulse amplifier, comprising:

an amplification medium and a normal dispersion medium that are multistage-connected alternately, to change an input pulse to a light pulse having a linear chirp in a bandwidth range of wider than that for the input pulse and to output the light pulse,

wherein the normal dispersion medium is a dispersion compensating medium and an absolute value of a dispersion of the normal dispersion medium is larger than an absolute value of a dispersion of the amplification medium,

wherein each subsequent stage of the multi-stage connected media increases an intensity of the output light pulse, and

wherein each subsequent stage of the multi-stage connected media widens a spectrum width of the output light pulse.

2. The pulse amplifier of claim 1,

wherein the multistage-connected media include at least three in total of the amplification media and the normal dispersion media that are multistage-connected alternately.

3. The pulse amplifier of claim 1 or 2,

wherein the amplification medium is a rare earth doped optical fiber.

4. The pulse amplifier of claim 3,

wherein the dispersion of the rare earth doped optical fiber is a normal dispersion.

5. The pulse amplifier of claim 1,

wherein the amplification medium and the normal dispersion medium are a polarization maintaining type.

6. The pulse amplifier of claim 1,

wherein a time waveform of the light pulse having the linear chirp is parabolic functional.

7. The pulse amplifier of claim 1,

wherein the normal dispersion media and the amplification media are multistage-connected as not less than three stages.

21. The pulse amplifier of claim 1, wherein the multistage-connected media include a plurality of the amplification media and a plurality of the normal dispersion media, each of the plurality of the amplification media used in each stage of the multi-stage connected media is the same, and each of the plurality of the normal dispersion media used in each stage of the multi-stage connected media is the same.

22. The pulse amplifier of claim 2,

wherein the multistage-connected media, which include at least three in total of the amplification media and the normal dispersion media, are arranged in a same package, a first isolator and a first wavelength divisional multiplex coupler are positioned at an input of the package, and a second isolator and a second wavelength divisional multiplex coupler are positioned at an output of the package.

23. The pulse amplifier of claim 3, wherein the normal dispersion medium is a dispersion compensation fiber.

25. The pulse amplifier of claim 4, wherein an absolute value of the accumulated dispersion is increased from an input to an output of the pulse amplifier.

8. A pulse light source, comprising:

a seed pulse generator for outputting a seed pulse; and

a pulse amplifier comprising an amplification medium and a normal dispersion medium that are multistage-connected alternately,

wherein the pulse amplifier changes an input pulse to a light pulse having a linear chirp in a bandwidth range of wider than that for the input pulse and outputs the light pulse,

wherein the normal dispersion medium is a dispersion compensating medium and an absolute value of a dispersion of the normal dispersion medium is larger than an absolute value of a dispersion of the amplification medium,

wherein each subsequent stage of the multi-stage connected media increases an intensity of the output light pulse, and

wherein each subsequent stage of the multi-stage connected media widens a spectrum width of the output light pulse.

9. The pulse light source of claim 8,

wherein the multistage-connected media include at least three in total of the amplification media and the normal dispersion media that are multistage-connected alternately.

10. The pulse light source of claim 8 or 9,

wherein the amplification medium is a rare earth doped optical fiber.

11. The pulse light source of claim 10,

wherein the dispersion of the rare earth doped optical fiber is a normal dispersion.

12. The pulse light source of claim 8,

wherein the amplification medium and the normal dispersion medium are a polarization maintaining type.

13. The pulse light source of claim 8,

wherein a time waveform of the light pulse having the linear chirp is parabolic functional.

14. The pulse light source of claim 8,

wherein a full width at half maximum of the seed pulse output from the seed pulse generator is not less than two picoseconds.

15. The pulse light source of claim 8,

wherein the seed pulse generator comprises a laser source of a direct modulating type for a semiconductor laser, as a seed pulse light source for outputting a seed pulse.

16. The pulse light source of claim 15,

wherein the laser source is a gain switch light source for gain switch driving the semiconductor laser.

17. The pulse light source of claim 8, further comprising:

a dispersion compensator for further dispersion compensating a light pulse output from the pulse amplifier.

18. The pulse light source of claim 17,

wherein the dispersion compensator is an anomalous dispersion fiber.

19. The pulse light source of claim 17,

wherein the dispersion compensator is comprised of a grating pair.

20. The pulse light source of claim 8,

wherein the normal dispersion media and the amplification media are multistage-connected as not less than three stages.

24. The pulse light source of claim 9,

wherein the multistage-connected media, which include at least three in total of the amplification media and the normal dispersion media, are arranged in a same package, a first isolator and a first wavelength divisional multiplex coupler are positioned at an input of the package, and a second isolator and a second wavelength divisional multiplex coupler are positioned at an output of the package.

26. The pulse light source of claim 8, further comprising:

a dispersion compensator arranged after an output of the pulse amplifier, wherein the dispersion compensator compresses a time of the output light pulse so that the time thereof becomes shorter than a time of the pulse of the light output from the seed pulse generator.

27. The pulse light source of claim 11, wherein an absolute value of the accumulated dispersion is increased from an input to an output of the pulse amplifier.

28. A pulse amplifier, comprising:

an amplification medium and a normal dispersion medium that are multistage-connected alternately, to change an input pulse to a light pulse having a linear chirp in a bandwidth range of wider than that for the input pulse and to output the light pulse,

wherein the normal dispersion medium is a dispersion compensating medium and an absolute value of a dispersion of the normal dispersion medium is larger than an absolute value of a dispersion of the amplification medium,

wherein the multistage-connected media include at least three in total of the amplification media and the normal dispersion media that are multistage-connected alternately, and

wherein the multistage-connected media, which include at least three in total of the amplification media and the normal dispersion media, are arranged in a same package, a first isolator and a first wavelength divisional multiplex coupler are positioned at an input of the package, and a second isolator and a second wavelength divisional multiplex coupler are positioned at an output of the package.

29. A pulse light source, comprising:

a seed pulse generator for outputting a seed pulse; and

a pulse amplifier comprising an amplification medium and a normal dispersion medium that are multistage-connected alternately,

wherein the pulse amplifier changes an input pulse to a light pulse having a linear chirp in a bandwidth range of wider than that for the input pulse and outputs the light pulse,

wherein the normal dispersion medium is a dispersion compensating medium and an absolute value of a dispersion of the normal dispersion medium is larger than an absolute value of a dispersion of the amplification medium,

wherein the multistage-connected media include at least three in total of the amplification media and the normal dispersion media that are multistage-connected alternately, and

wherein the multistage-connected media, which include at least three in total of the amplification media and the normal dispersion media, are arranged in a same package, a first isolator and a first wavelength divisional multiplex coupler are positioned at an input of the package, and a second isolator and a second wavelength divisional multiplex coupler are positioned at an output of the package.