Stimulated Raman scattering influenced by concentration,fluorescence profile and bandwidth of β‐carotene in liquid‐core optical fiber

We demonstrated stimulated Raman scattering (SRS) of carbon disulfide (CS₂) influenced by β‐carotene in a liquid‐core optical fiber (LCOF). Owing to the double fluorescence characteristics and large third‐order optical nonlinearity of β‐carotene, the high‐order Stokes lines, such as the seventh‐order Stokes line of CS₂, can be observed at a relatively low input‐laser power. The thresholds of Stokes lines lowered with the addition of the carotenoid when the concentration of solution was within 10⁻¹² and 10⁻⁷ mol/L; the threshold increments and intensities of Stokes lines were correlative with the fluorescence profile of β‐carotene: when the fluorescence intensity of the wavenumber region on the spectrum was high, the Stokes line intensity was also high and its threshold increment was small, and vice versa. These results are expected to be worthy of the applications on the tunable laser and the seeding laser. Copyright © 2009 John Wiley & Sons, Ltd.