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Title: 1-D imaging of rotation-vibration non-equilibrium from pure rotational ultrafast coherent anti-Stokes Raman scattering

We present one-dimensional (1-D) imaging of rotation-vibration non-equilibrium measured by two-beam pure rotational hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS). Simultaneous measurements of the spatial distribution of molecular rotation-vibration non-equilibrium are critical for understanding molecular energy transfer in low temperature plasmas and hypersonic flows. However, non-equilibrium CARS thermometry until now was limited to point measurements. The red shift of rotational energy levels by vibrational excitation was used to determine the rotational and vibrational temperatures from 1-D images of the pure rotational spectrum. Vibrational temperatures up to 5500 K were detected in aCH4/N2nanosecond-pulsed pin-to-pin plasma within 2 mm near the cathode. This approach enables study of non-equilibrium systems with 40 µm spatial resolution.

 
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NSF-PAR ID:
10371396
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Optical Society of America
Date Published:
Journal Name:
Optics Letters
Volume:
45
Issue:
15
ISSN:
0146-9592; OPLEDP
Page Range / eLocation ID:
Article No. 4252
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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