INEXPENSIVE VARIABLE REP-RATE SOURCE FOR HIGH-ENERGY, ULTRAFAST LASERS

• US 20090097520A1
• Filed: 12/19/2008
• Published: 04/16/2009
• Est. Priority Date: 05/14/2003
• Status: Active Grant

• Current Assignee: IMRA America Incorporated (Aisin Corp.)
• Original Assignee: IMRA America Incorporated (Aisin Corp.)
• Inventors: HARTER, Donald J.
• Granted Patent: US 8,248,690 B2
• Time in Patent Office: Days
• US Class Current: 372/44.01
• CPC Class Codes: G02B 6/2932 comprising a directional router, e.g. directional coupler, circulator
• CPC Class Codes: G02B 6/29374 in an optical light guide G02B6/02214 takes precedence
• 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 3/067 Fibre lasers
• CPC Class Codes: H01S 3/06708 Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering optical fibres as passive waveguides G02B6/02
• CPC Class Codes: H01S 3/06716 Fibre compositions per se C03C13/04or doping with active elements lasing materials in general H01S3/14
• 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 3/0675 Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/06758 Tandem amplifiers
• CPC Class Codes: H01S 3/08013 Resonator comprising a fibre, e.g. for modifying dispersion or repetition rate the active medium being a fibre H01S3/067
• CPC Class Codes: H01S 3/094003 the pumped medium being a fibre
• CPC Class Codes: H01S 3/094076 Pulsed or modulated pumping H01S3/1024 takes precedence
• CPC Class Codes: H01S 3/0941 of a laser diode
• CPC Class Codes: H01S 3/10046 Pulse repetition rate control H01S3/11 takes precedence
• CPC Class Codes: H01S 3/1106 Mode locking
• CPC Class Codes: H01S 3/115 using intracavity electro-optic devices
• CPC Class Codes: H01S 3/1608 erbium
• CPC Class Codes: H01S 3/1618 ytterbium
• CPC Class Codes: H01S 3/2308 Amplifier arrangements, e.g. MOPA
• CPC Class Codes: H01S 3/2375 : Hybrid lasers H01S3/07 takes precedence
• CPC Class Codes: H01S 5/0057 : for temporal shaping, e.g. pulse compression, frequency chirping
• CPC Class Codes: H01S 5/0085 : for modulating the output, i.e. the laser beam is modulated outside the laser cavity
• CPC Class Codes: H01S 5/06216 : Pulse modulation or generation
• CPC Class Codes: H01S 5/12 : the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers comprising a photonic bandgap structure H01S5/11; surface-emitting lasers H01S5/18
• CPC Class Codes: H04B 10/508 : Pulse generation, e.g. generation of solitons

Abstract

System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.

Claims

1. A system comprising:

a microchip laser outputting pulses;

a fiber with positive group-velocity dispersion (GVD) and self-phase modulation (SPM) receiving an output of said microchip laser and producing output pulses compressible to pulse widths of about 10 ps or less; and

a pump source for pumping said microchip laser.

2. The system according to claim 1, wherein a compressible output pulse comprises a pulse having a pulse width of about 250 ps.

3. The system according to claim 1, wherein an output of said microchip laser comprises a pulse having a pulse width in the range of from 50 ps to 10 ns.

4. The system according to claim 1, wherein said microchip laser outputs pulses greater than 1 ps

5. The system according to claim 1, further comprising a compressor receiving a compressible output from said fiber and producing a compressed output pulse having a pulse width less than about 10 ps.

6. The system according to claim 5, further comprising a gain switched laser pumped by an output of said compressor.

7. The system according to claim 1, wherein said pump source is gain-switched.

8. The system according to claim 1, wherein said fiber comprises a single-mode fiber.

9. The system according to claim 1, wherein said fiber comprises a multimode fiber.

10. The system according to claim 9, wherein said multimode fiber is configured to propagate a single mode beam.

11. The system according to claim 1, wherein said fiber comprises a holey fiber.

12. The system according to claim 1, wherein said fiber comprises a coreless end cap, whereby a mode is expanded before a surface of said fiber.

13. The system according to claim 1, wherein said fiber comprises a multi-mode, Yb gain fiber configured as a Yb fiber amplifier.

14. The system according to claim 1, wherein an output of microchip laser comprises a pulse having pulse energy greater than 500 nJ.

15. The system according to claim 1, further comprising a conversion crystal disposed downstream from said fiber for varying the wavelength of an output of said system.

16. The system according to claim 15, wherein said system having said conversion crystal is configured to operate in the UV spectrum.

17. The system according to claim 1, wherein said fiber and microchip laser are configured in such a way that Raman generation within said fiber is limited.

18. The system according to claim 1, wherein said microchip laser is configured for variable repetition rates.

19. The system according to claim 1, wherein said microchip laser is q-switched.

20. A system comprising:

a non-mode-locked source laser generating output pulses; and

a fiber with positive group-velocity dispersion (GVD) and self-phase modulation receiving an output of said non-mode-locked source and producing output pulses compressible to pulse widths of about 10 ps or less; and

a pump source for pumping said microchip laser.

21. The system of claim 20, wherein said non-mode-locked source comprises a microchip laser.

22. The system of claim 20, wherein said non-mode-locked source comprises a cw laser diode and an lithium niobate electro-optic modulator disposed at an output of said cw laser diode.

23. The system of claim 20, further comprising a conversion crystal disposed downstream from said fiber for varying the wavelength of an output of said system.

24. The system according to claim 23, wherein said system having said conversion crystal is configured to operate in the UV spectrum.

25. The system according to claimed in claim 20, wherein said fiber is a single mode fiber having a length of approximately 2 meters for a compression ratio of approximately 50.