Efficient generation of multi-order Raman radiation in aqueous solutions derived from-CH2 and-NH2 vibrations via cascaded four-wave mixing and Stokes processes

Multiple coherent radiations are achieved in a water-3aminopropanol (3AP) mixed solution through cascaded four-wave mixing (C-FWM) and cascaded Stokes (C-Stokes) processes, both driven by stimulated Raman scattering (SRS) in this work. The O-H vibration peak from water is replaced by the emergence of the -NH2 symmetric stretching Raman peaks from 3AP, with intensity approaching that of the -CH2 symmetric stretching peak. The dual- wavelength SRS signals for the -NH2 and -CH2 stretching vibrations have a relatively small frequency interval of about 400 cm-1 (16 nm). By varying the 3AP concentration and pump energy, these two peaks from 3AP act as new pump sources, enabling the successful generation of up to 16th- order Stokes and 5th-order anti-Stokes radiation through C-FWM and C-Stokes processes. The resulting spectrum spans a broad wavenumber range from - 3318 to 6629 cm-1 (452 to 822 nm), offering a new approach for broadband coherent light sources and multi-order Raman spectra in liquid media. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.