High-order parametric generation of coherent XUV radiation

Area of Science:

• Quantum optics
• Attosecond science
• Nonlinear optics

Background:

• Extreme ultraviolet (XUV) radiation is crucial for spectroscopy and studying ultrafast phenomena.
• High-order harmonic generation (HHG) produces attosecond pulses but suffers from limited efficiency.

Purpose of the Study:

• To introduce a novel regime of coherent XUV emission with potential for higher intensity.
• To overcome the efficiency limitations of traditional high-order harmonic generation (HHG).

Main Methods:

• Observation of a new coherent XUV emission process.
• Explanation via high-order parametric generation involving THz and XUV photon emission.
• Demonstration of robust phase matching against ionization.

Main Results:

• A new regime of coherent XUV emission was observed.
• The process involves simultaneous emission of THz and XUV photons.
• The phase matching proved highly robust against ionization.

Conclusions:

• High-order parametric generation offers a promising route to higher XUV intensity.
• This method enables the use of higher-energy driving pulses for increased XUV photon generation.
• The robust phase matching facilitates practical applications in ultrafast science.