title: Controlling cross pumping between C-N and C-H vibration in nitromethane by selective fluorescence-enhanced stimulated Raman scattering.
abstract: To investigate the vibrational features of nitromethane (NM), which is a kind of energy material and a well known low-sensitivity and high explosive, experiments are performed to obtain the stimulated Raman scattering (SRS) of NM by employing a 532 nm pulsed pump laser. The Raman signal involves two stimulated emissions at 918 and 2,963 cm-1, attributed to the C-N and C-H stretching vibrations, respectively. To overcome the complexity of cross pump in the pure NM, one stimulated Raman radiation is chosen as a pump source to excite the other Raman mode. Two fluorescence dyes were added to selectively enhance each Raman cross section. By internally seeding the Raman gain medium with fluorescent photons, a significant modification in the stimulated Raman scattering spectrum has been observed. The enhanced Stokes emission at 918 cm-1was able to induce the 2,963 cm-1vibration mode when the all-trans-β-carotene was internal seeding in the NM, while the Raman radiation at 2,963 cm-1was enhanced to excite the C-N mode with the addition of m-Cresol purple. The output energy of both 918 and 2,963 cm-1under different input energy was also measured to illustrate this result.
authors.forename: Shenghan
authors.initials: S
authors.lastname: Wang
authors.forename: Wenhui
authors.initials: W
authors.lastname: Fang
authors.forename: Tianyu
authors.initials: T
authors.lastname: Li
authors.forename: Fangfang
authors.initials: F
authors.lastname: Li
authors.forename: Chenglin
authors.initials: C
authors.lastname: Sun
authors.forename: Zuowei
authors.initials: Z
authors.lastname: Li
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Men