New Laser Sources

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New Laser Sources
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High Harmonic Generation in Gases
Phenomenology ?Spectrum has a plateau ?Spectrum
has a cut off ?With higher frequency the plateau
is shorter, but its intensity is stronger
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Typical Experimental Geometry

• Laser
• Peak Intensity
• I 1015 W/cm2
• 0.75?
• 100fs
• Linear polarized

Gas Jet h1mm, ?1018 cm-3
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Simple Men Theory
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Time of Birth and Electron Trajectory
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Dependence on the laser frequency
Intensity of Harmonics generated from He, Ne, Ar,
Kr, Xe by DYE laser ?0.616? (left picture) and
KrF laser ?0.248? (right picture)
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(No Transcript)
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Pre- and Post-Harmonics
On each period of the laser radiation each
harmonics is generated twice
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Focusing of the Harmonics
For the beam axis
For the beam edges
nhw
tpre
tpost
Harmonics are naturally focused
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Toward to Atto-Second pulses
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Toward to Atto-Second pulses
Perform a filtering of the Harmonics (No. 35-55)
By filtering we get a train of Impulses with
frequency of w(3555)/2
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The End

• References
• V. Platonenko High
• Harmonic Generation in
• Intense Laser Fields
• Quantum Electronics, 25, No7
• (1998)
• 2) M. Protopapas Atomic
• physics with super-high
• intensity lasers Rep. Prog. Phys.
• 60 (1997) 389-486