Switched Supercontinuum Coherent Radiation and Coherent Raman Comb by Four-Wave Mixing and Cross-Pumping from...

A scheme of switching supercontinuum coherent radiation and a coherent Raman comb is proposed, based on stimulated Raman scattering (SRS)-induced four-wave mixing (FWM) and the cross-pumping effect in cyclohexane (C₆H₁₂)/carbon tetrachloride (CCl₄) mixtures. C₆H₁₂ exhibits two SRS peaks (ν₁ and ν₂), attributed to the symmetric and antisymmetric stretching of -CH₂, respectively. Supercontinuum coherent radiation via FWM between the second-order Stokes SRS (ω₁) of ν₁ and the sum frequency (ω₂) of ν₁ and ν₂ is generated at a volume ratio of 3:7, which contains 13 peaks with a frequency interval of approximately 85 cm^-1, spanning a radiation bandwidth from 4850 to 5897 cm^-1. The SRS peak of CCl₄ appears at 456 cm^-1 (ν₃, C-Cl symmetric stretching), which cross-pumps with -CH₂ vibrational modes (ν₁ and ν₂) at a volume ratio of 2:8 to produce a coherent Raman comb spanning a bandwidth of 5717 cm^-1 with a frequency interval of 460 cm^-1. This research has the potential to be used for multiwavelength Raman lasers and precision measurements in time-frequency domains.