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Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Molecular high harmonic generation in a two-color field
Pengfei Wei1, Candong Liu, Chunmei Zhang
1State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
Optics Express
|July 1, 2010
Summary
A longer laser wavelength component can suppress high harmonic generation (HHG) in methane (CH4) molecules. This effect, observed by controlling laser timing and intensity, highlights wavelength-dependent HHG suppression in molecules.
Area of Science:
- Attosecond science and strong-field physics
- Molecular dynamics and quantum optics
Background:
- High harmonic generation (HHG) is a fundamental process in strong-field physics, producing extreme ultraviolet (XUV) and soft X-ray radiation.
- Understanding HHG in molecules is crucial for applications like attosecond spectroscopy and chemical dynamics imaging.
- The influence of multi-color laser fields on molecular HHG is an active area of research.
Purpose of the Study:
- To experimentally investigate the effect of a two-color laser field on high harmonic generation (HHG) from methane (CH4) molecules and xenon (Xe) atoms.
- To explore the role of a longer wavelength component (1500-1900 nm) in modulating the HHG process.
- To understand the wavelength-dependent suppression and enhancement mechanisms in molecular and atomic HHG.
Main Methods:
- Experimental setup utilizing a two-color laser field, combining an 800 nm laser and a tunable laser (1500-1900 nm).
- Controlled variation of the time delay between the two laser pulses.
- Tuning of the laser intensity of the longer wavelength component.
Main Results:
- The longer wavelength component was observed to destructively suppress HHG from CH4 molecules.
- Controlling the time delay or intensity of the longer wavelength component led to suppression of CH4 HHG and enhancement of Xe HHG under identical conditions.
- The suppression of molecular HHG was linked to the longer wavelength component interacting with molecular infrared absorption.
Conclusions:
- A longer wavelength laser component can significantly suppress molecular high harmonic generation (HHG).
- This suppression is wavelength-dependent and can be controlled by laser parameters, offering a method to tailor HHG.
- The findings provide insights into controlling molecular HHG and its interaction with molecular resonances.
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