Time-delayed Raman-enhanced nondegenerate four-wave mixing with a broadband laser source

Abstract

We report an experiment of the time-delayed Raman-enhanced nondegenerate four-wave mixing (RENFWM) with a broadband laser in carbon disulfide (CS2). We studied the RENFWM signal intensity as a function of the relative time delay~between two beams which originate from a single broadband laser source. Our results indicate that the temporal behavior of the RENFWM is asymmetric with the maximum of the signal shifted from~=0. Furthermore, unlike the corresponding coherent Stokes Raman scattering (CSRS) no coherent spike appears at~=0. From our experimental results the relaxation time of the Raman mode can be extracted directly. We present a second-order coherence function theory to elucidate the physics of the basic features of the time-delayed RENFWM. We also discuss the difference between the RENFWM and the CSRS from a physical viewpoint.PACS number(s): 42.65.Dr, 42.65.Hw

Six-wave mixing spectroscopy in a Doppler-broadened cascade four-level system

“…Up to now, most of these studies have been concerned with four-wave mixing (FWM). For example, several resonance-enhanced nondegenerate fourwave mixing (NFWM) schemes have been developed by our laboratory for various spectroscopic purposes [2][3][4][5]. Specifically, NFWM involves two frequencies, and, according to different resonance situations, resonant NFWM can correspond to two-colour laser-induced grating spectroscopy, two-photon spectroscopy [3] or coherent Raman spectroscopy [4].…”

“…For example, several resonance-enhanced nondegenerate fourwave mixing (NFWM) schemes have been developed by our laboratory for various spectroscopic purposes [2][3][4][5]. Specifically, NFWM involves two frequencies, and, according to different resonance situations, resonant NFWM can correspond to two-colour laser-induced grating spectroscopy, two-photon spectroscopy [3] or coherent Raman spectroscopy [4]. Moreover, if an additional strong coupling field is applied, then the NFWM spectrum exhibits Autler-Townes (AT) splitting, accompanied by either suppression or enhancement of the NFWM signal [5].…”