Raman linewidth measurements using time-resolved hybrid picosecond/nanosecond rotational CARS

Summary, in English

We report an innovative approach for time-domain measurements of S-branch Raman linewidths using hybrid picosecond/nanosecond pure-rotational coherent anti-Stokes Raman spectroscopy (RCARS). The Raman coherences are created by two picosecond excitation pulses and are probed using a narrow-band nanosecond pulse at 532 nm. The generated RCARS signal contains the entire coherence decay in a single pulse. By extracting the decay times of the individual transitions, the J-dependent Raman linewidths can be calculated. Self-broadened S-branch linewidths for nitrogen and oxygen at 293 K and ambient pressure are in good agreement with previous time-domain measurements. Experimental considerations of the approach are discussed along with its merits and limitations. The approach can be extended to a wide range of pressures and temperatures and has potential for simultaneous single-shot thermometry and linewidth determination. (C) 2015 Optical Society of America

• Author: Emil Nordström; Ali Hosseinnia; Christian Brackmann; Joakim Bood; Per-Erik Bengtsson
• Department/s: Combustion Physics
• Publishing year: 2015
• Language: English
• Pages: 5718-5721
• Publication/Series: Optics Letters
• Volume: 40
• Issue: 24
• Links: http://dx.doi.org/10.1364/OL.40.005718
• Document type: Journal article
• Publisher: Optical Society of America
• Topic: Atom and Molecular Physics and Optics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0146-9592