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Published on: August 1, 2017
White-light-induced fragmentation of methane
Deepak Mathur1, Firoz A Rajgara, Aditya K Dharmadhikari
1Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India. atmol1@tifr.res.in
The Journal of Physical Chemistry. A
|August 25, 2007
Summary
Researchers studied methane ionization and dissociation using intense, broadband white light. They found that resonances and polarization do not affect ionization dynamics with this light source.
Area of Science:
- Physical Chemistry
- Atomic, Molecular, and Optical Physics
- Laser Physics
Background:
- Investigating molecular response to intense laser fields is crucial for understanding fundamental light-matter interactions.
- Broadband light sources offer unique opportunities to probe complex dynamics not accessible with monochromatic light.
Purpose of the Study:
- To experimentally investigate the ionization and dissociation dynamics of methane molecules using intense broadband white light.
- To estimate the in situ intensity of white light pulses by comparing fragmentation patterns with single-color laser light.
- To determine the role of resonances and polarization in ionization dynamics under broadband irradiation.
Main Methods:
- Generation of broadband white light pulses by irradiating BK7 glass with intense 820 nm laser pulses.
- Experimental probing of methane ionization and dissociation using the generated white light (500-850 nm).
- Comparison of molecular fragmentation patterns obtained with depolarized white light and highly chirped single-color (820 nm) light.
Main Results:
- Methane molecules were ionized and dissociated by intense white light pulses.
- Hitherto-unavailable estimates of in situ white light pulse intensity were obtained.
- Results indicate that resonances do not play a significant role in ionization dynamics under intense, broadband light.
- Ionization dynamics were found to be unaffected by the polarization properties of the 820 nm laser used for white light generation.
Conclusions:
- Intense broadband white light can effectively induce molecular ionization and dissociation in methane.
- The study provides a method for estimating the intensity of broadband pulses in situ.
- Ionization dynamics of methane under intense broadband light are independent of resonant effects and the polarization of the generating laser.
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