Very high power pulsed fiber laser
A high power integrated fiber laser system includes cascaded amplifiers that utilize low numerical aperture fiber amplifiers. The system is rugged and lightweight.
1. A fiber laser amplifier comprising:
a seed laser configured to produce a seed pulse at a pulse repetition rate of about 10 Hz to about 100 Hz;
a fiber preamplifier configured to receive and amplify the seed pulse, said fiber preamplifier having a first core diameter;
a fiber power amplifier comprising a low numerical aperture, coiled clad fiber, having a core diameter larger than said first core diameter; and
a coupler configured to couple said fiber preamplifier to said fiber power amplifier.
2. The fiber laser amplifier according to claim 1 , wherein said low numerical aperture is between about 0.06 and 0.08.
3. The fiber laser amplifier according to claim 1 , further comprising a tapered fiber bundle connected to a cladding of said fiber power amplifier configured to direct pump energy into said cladding.
4. The fiber laser amplifier according to claim 1 , further comprising:
a first pumping device configured to pump said fiber preamplifier,
a second pumping device configured to pump said fiber power amplifier, and
a synchronizing device configured to synchronize the seed pulse with said pumping devices.
5. The fiber laser amplifier according to claim 1 , further comprising one or more additional power amplifiers, wherein the core diameter each additional power amplifier increases with each subsequent power amplifier stage.
6. A method comprising:
producing a seed pulse with a pulse repetition rate of about 10 Hz to about 100 Hz;
amplifying the seed pulse using a fiber preamplifier having a first core diameter; and
amplifying the amplified seed pulse using a fiber power amplifier that is coupled to the fiber preamplifier and that comprises a low numerical aperture, coiled clad fiber, having a second core diameter, the second core diameter being larger than the first core diameter.
7. The method of claim 6 , further comprising:
pumping the fiber preamplifier using a first pumping device;
pumping the fiber power amplifier using a second pumping device; and
synchronizing the seed pulse with the first and second pumping devices.
8. The method of claim 6 , further comprising:
directing pump energy into a cladding of the fiber power amplifier using a tapered fiber bundle.
9. A pulsed fiber laser comprising:
a seed laser configured to produce a seed pulse at a pulse repetition rate of about 10 Hz to about 100 Hz;
a first amplifier configured to receive and amplify the seed pulse, the first amplifier having a first core diameter;
a second amplifier comprising coiled clad fiber having a second core diameter, the second core diameter being larger than the first core diameter; and
a coupler configured to couple the first and second amplifiers;
wherein core diameters of the second amplifier and subsequent amplifiers increase with each subsequent amplifier stage.
10. The pulsed fiber laser of claim 9 , further comprising a tapered fiber bundle connected to a cladding of the second amplifier configured to direct pump energy into the cladding.
11. The pulsed fiber laser of claim 9 , further comprising:
a first pumping device configured to pump the first amplifier,
a second pumping device configured to pump the second amplifier, and
a synchronizing device configured to synchronize the seed pulse with the pumping devices.
12. The pulsed fiber laser of claim 9 , wherein the fiber of the second amplifier comprises a low numerical aperture.