Optical parametric amplification, optical parametric generation, and optical pumping in optical fibers systems

• US 20050238070A1
• Filed: 03/25/2005
• Published: 10/27/2005
• Est. Priority Date: 03/25/2004
• Status: Active Grant

• Current Assignee: IMRA America Incorporated (Aisin Corp.)
• Original Assignee: IMRA America Incorporated (Aisin Corp.)
• Inventors: Fermann, Martin, Imeshev, Gennady
• Granted Patent: US 8,040,929 B2
• Time in Patent Office: Days
• US Class Current: 372/21
• CPC Class Codes: G02F 1/3558 Poled materials, e.g. with periodic poling; Fabrication of domain inverted structures, e.g. for quasi-phase-matching [QPM]
• CPC Class Codes: G02F 1/39 for parametric generation or amplification of light, infrared or ultraviolet waves
• CPC Class Codes: G02F 1/392 Parametric amplification
• CPC Class Codes: G02F 2203/26 Pulse shaping; Apparatus or methods therefor
• CPC Class Codes: H01S 3/005 Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B
• 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 3/06708 Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering optical fibres as passive waveguides G02B6/02
• CPC Class Codes: H01S 3/06725 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 3/06758 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 3/0941 of a laser diode
• CPC Class Codes: H01S 3/10015 by monitoring or controlling, e.g. attenuating, the input signal
• CPC Class Codes: H01S 3/10092 Coherent seed, e.g. injection locking
• CPC Class Codes: H01S 3/109 Frequency multiplication, e.g. harmonic generation
• CPC Class Codes: H01S 3/1608 erbium
• CPC Class Codes: H01S 3/1616 thulium
• CPC Class Codes: H01S 3/302 in an optical fibre

Abstract

Embodiments described herein include a system for producing ultrashort tunable pulses based on ultra broadband OPA or OPG in nonlinear materials. The system parameters such as the nonlinear material, pump wavelengths, quasi-phase matching periods, and temperatures can be selected to utilize the intrinsic dispersion relations for such material to produce bandwidth limited or nearly bandwidth limited pulse compression. Compact high average power sources of short optical pulses tunable in the wavelength range of 1800-2100 nm and after frequency doubling in the wavelength range of 900-1050 nm can be used as a pump for the ultra broadband OPA or OPG. In certain embodiments, these short pump pulses are obtained from an Er fiber oscillator at about 1550 nm, amplified in Er fiber, Raman-shifted to 1800-2100 nm, stretched in a fiber stretcher, and amplified in Tm-doped fiber. To produce short pulses in the 900-1050 nm wavelength range, the pulses are frequency-doubled with a chirped frequency doubler for nearly bandwidth-limited output.

Claims

1. A pulsed light source based on optical parametric generation comprising:

a pump laser configured to output optical pulses having a pulse width of about 10 nanoseconds or less; and

a nonlinear crystal selected from the group comprising periodically poled lithium-niobate, periodically poled KTP, periodically-twinned quartz, periodically poled RTA, periodically poled lithium tantalate, and periodically poled potassium niobate,

wherein said optical pulses from said pump laser pump said nonlinear crystal thereby producing optical parametric generation having a bandwidth of at least about 200 nanometers.

2. The pulsed light source of claim 1, wherein said nonlinear crystal is pumped with optical pulses having an energy of about 1 microjoule (μ

J) or less and obtains a parametric gain of about 10 dB or higher

3. The pulsed light source of claim 1, further comprising a fiber amplifier optically coupled to said pump laser so as to receive and amplify said optical pulses for pumping said nonlinear crystal.

4. The pulsed light source of claim 1, further comprising a seed source upstream from said pump laser, said seed source further comprising a supercontinuum fiber, said seed source configured to seed an amplifier for pumping said nonlinear crystal.

5. The pulsed light source of claim 1, further comprising:

a Raman shifting fiber optically coupled to said pump laser and configured to shift the wavelength of said optical pulses output by said pump laser; and

a frequency doubler optically disposed to receive said wavelength shifted optical pulses and configured to increase the frequency of said wavelength shifted optical pulses, said wavelength shifted optical pulses pumping said periodically poled nonlinear crystal to produce optical parametric generation.

6. A pulsed light source based on optical parametric generation comprising:

a pump fiber laser; and

a nonlinear crystal selected from the group comprising periodically poled lithium-niobate, periodically poled KTP, periodically-poled quartz, periodically poled RTA, periodically poled lithium tantalate, periodically poled potassium niobate and orientation patterned GaAs,

wherein said pump fiber laser is configured to provide pump energy to said nonlinear crystal so as to produce spectral emission via optical parametric generation in a spectral range exceeding a width of about 100 nanometers.

7. The pulsed light source of claim 6, wherein said nonlinear crystal is pumped with optical pulses having an energy of less than about 10 μ

J and obtains a parametric gain of about 10 dB or higher.

8. The pulsed light source of claim 6, wherein said nonlinear crystal has non-constant periodic poling.

9. The pulsed light source of claim 8, wherein said nonlinear crystal has chirped poling.

10. A pulsed light source based on optical parametric amplification comprising:

a fiber pump laser;

a fiber continuum source; and

a nonlinear crystal that receives optical pulses from said fiber pump laser and optical pulses from said fiber continuum source, said optical pulses from said fiber continuum source being amplified by optical parametric amplification in said nonlinear crystal,

wherein said optical pulses from said fiber pump laser and said optical pulses from said fiber continuum source are substantially synchronized in time.

11. The pulsed light source of claim 10, wherein said fiber pump laser comprises Nd-doped amplifying fiber, Yb-doped amplifying fiber, Er-doped amplifying fiber, Er/Yb-doped amplifying fiber, Tm-doped amplifying fiber or Ho-doped amplifying fiber.

12. The pulsed light source of claim 10, wherein said optical pulses from said fiber pump laser and said optical pulses from said fiber continuum source have substantially the same pulse width.

13. The pulsed light source of claim 10, wherein said optical pulses from said fiber pump laser and said optical pulses from said fiber continuum source have pulse widths that differ by no more than about a factor of ten.

14. The pulsed light source of claim 10, wherein said optical pulses from said fiber pump laser and said optical pulses from said fiber continuum source substantially overlap.

15. The pulsed light source of claim 10, wherein said optical pulses from said fiber pump laser and said optical pulses from said fiber continuum source, said overlap comprising at least about 10% of the pulse duration of said optical pulses from said fiber continuum source.

16. A pulsed light source based on optical parametric amplification comprising:

a pump laser;

a seed source comprising an optical continuum fiber; and

a nonlinear crystal that receives optical pulses from said pump laser and optical pulses from said seed source, said optical pulses from said seed source being amplified by optical parametric amplification in said nonlinear crystal,

wherein said optical pulses from said pump laser and said optical pulses from said seed source are substantially synchronized in time.

17. The pulsed light source of claim 16, wherein said seed source is disposed to receive optical pulses from said pump laser such that said optical pulses from said pump laser and said optical pulses from said seed source are substantially synchronized in time.

18. The pulsed light source of claim 16, wherein said nonlinear crystal is periodically poled, said poling period being non-constant.

19. A pulsed light source according to claim 18, wherein said poling period is chirped.

20. A pulsed light source according to claim 16, wherein said nonlinear crystal is selected from a family comprising periodically poled lithium-niobate, periodically poled KTP, periodically poled quartz, periodically poled RTA, periodically poled lithium tantalate, periodically poled potassium niobate and orientation patterned GaAs.

21. A pulsed light source based on optical parametric amplification comprising:

a pump laser source;

a seed source; and

a nonlinear crystal that receives optical pulses from said pump laser source and optical pulses from said seed source and produces spectral emission as a result of optical parametric amplification, said spectral emission having a spectral range exceeding a width of about 100 nanometers.

22-66. -66. (canceled)