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US 2003/0189959 A1Published application
Application of Yb:YAG short pulse laser system
AssigneeThe Regents of the University of California
InventorsGaylen V. Erbert, Subrat Biswal, Joseph M. Bartolick, Brent C. Stuart, John K. Crane, Steve Telford, Michael D. Perry
Life of this patent
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Abstract
A diode pumped, high power (at least 20W), short pulse (up to 2 ps), chirped pulse amplified laser using Yb:YAG as the gain material is employed for material processing. Yb:YAG is used as the gain medium for both a regenerative amplifier and a high power 4-pass amplifier. A single common reflective grating optical device is used to both stretch pulses for amplification purposes and to recompress amplified pulses before being directed to a workpiece.
Claims80
An apparatus, comprising:
- a source of laser pulses, a pulse stretcher-compressor adapted for stretching said laser pulses to produce one or more stretched laser pulses and adapted for producing one or more compressed amplified laser pulses obtained from stretched amplified laser pulses received from an amplifier,
- an amplifier, constructed to receive each of said stretched pulses to produce amplified stretched pulses,
- means for maintaining alignment of said stretched laser pulses and said compressed amplified pulses, and maintaining power levels of said source of laser pulses and said amplifier;
- and
- means for directing said compressed amplified pulses toward a workpiece.
2 more elements
An apparatus for material processing, comprising:
- a source of laser pulses,
- a pulse stretcher-compressor adapted for stretching said laser pulses to produce one or more stretched laser pulses and adapted for producing one or more compressed second amplified laser pulses obtained from a power amplifier,
- a pre-amplifier, comprising Yb:YAG lasing material, constructed to receive each of said stretched pulses to produce amplified stretched pulses,
- a power amplifier, comprising at least 1 Yb:YAG head, constructed to receive each of said amplified stretched pulses directed from said pre-amplifier to produce second amplified stretched pulses,
- means for maintaining alignment of said stretched laser pulses and said compressed second amplified pulses, and maintaining power levels of said source of laser pulses, said pre-amplifier and said power amplifier;
- and
- means for directing said compressed second amplified laser pulses toward a workpiece.
4 more elements
A method for machining materials, comprising:
- producing a laser source of pulses,
- optically stretching said laser pulses,
- amplifying a predetermined energy of each of said stretched laser pulses,
- optically compressing said stretched laser pulses to produce one or more amplified compressed laser pulses, wherein said stretched laser pulses and said one or more amplified compressed laser pulses are interleaved along a common area from a single common reflective diffraction grating,
- maintaining alignment of said laser source of pulses, said stretched laser pulses, said one or more compressed amplified pulses, and maintaining power levels of said laser pulses from said laser source of pulses and said one or more amplified compressed laser pulses;
- and
- directing said one or more compressed amplified laser pulses toward a workpiece.
4 more elements
A method for machining materials, comprising:
- producing a laser source of pulses,
- optically stretching said laser pulses,
- first amplifying a predetermined energy of each of said optically stretched laser pulses, wherein a pre-amplifier, comprising Yb:YAG lasing material, is constructed to produce first amplified stretched pulses,
- second amplifying the energy of each of said first amplified stretched laser pulses, wherein a power amplifier, comprising at least 1 Yb:YAG head, is constructed to produce second amplified stretched pulses,
- optically compressing said second amplified stretched pulses to produce second amplified compressed pulses,
- maintaining alignment of said laser source of pulses, said first amplified stretched pulses, said second amplified stretched pulses and said second amplified compressed pulses, and maintaining power levels of said laser pulses from said laser source, said pre-amplifier and said power amplifier;
- and
- directing said second amplified compressed pulses toward a workpiece.
5 more elements
A method for machining materials, comprising:
- producing a pulsed laser output beam comprising a plurality of pulses wherein each pulse of said plurality of pulses has an energy and a pulse repetition rate controlled to attain at least 20 Watts of average power;
- and
- directing said pulsed laser output beam onto a workpiece, wherein said plurality of laser pulses has a pulse duration from about 0.05 to less than about 10 picoseconds, a bandwidth between about 1.5 and about 35 nm, and a focused fluence from about 0.1 to less that about 20 J/cm2, wherein each said pulse converts from about 0.01 to less than about 1 micron of material of said workpiece from the solid state to the plasma state, wherein said material is removed from said workpiece by hydrodynamic expansion of said plasma.
Dependencies are inferred from the claim text.