Abstract
Cavity ringdown (CRD) spectroscopy is extended for the first time from its conventional optical-absorption mode of operation into the regime of coherent Raman spectroscopy. Continuous-wave (cw) stimulated Raman gain (SRG) spectra of the 2916.5-cm-1 ν1 rovibrational fundamental Raman band of methane (CH4) gas are measured, using tunable cw laser light at ∼1544 nm to probe ringdown decay from a rapidly swept optical cavity that is itself inside the cavity of a cw single-longitudinal-mode Nd:YAG ring laser operating at ∼1064.5 nm. The resulting change of ringdown decay rate is dependent on pump laser irradiance and is associated with Raman gain. Remarkably, such SRG-CRD resonances display ringdown times that are longer than in the off-resonance case, contrasting with the usual reduction of ringdown time associated with absorption and other loss processes.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
