Stimulated supercontinuum-radiation generation of carbon disulfide by all-trans-β-carotene fluorescence enhancement effect in liquid core optical fibre

We demonstrate stimulated supercontinuum-radiation of carbon disulfide (CS₂) influenced by biological molecules all-trans-β-carotene in liquid core optical fibre (LCOF). By virtue of the broad fluorescence characteristics and large third-order optical nonlinearities of all-trans-β-carotene,the high-order Stokes lines of stimulated Raman scattering (SRS) and the multi-order Stokes lines of stimulated Brillouin scattering (SBS) excitated by SRS are observed at low input-laser energies. The results indicate that the fluorescence not only enhances the SRS, but also the SBS. These Stokes lines generate the SRS–SBS supercontinuum radiation (RBSR). A flat-amplitude bandwidth of 110 nm from 515nm to 625nm is observed when a frequency-doubled Nd:YAG laser at 532nm with an energy of 0.86mJ is used. This result is expected to be useful for the multi-wavelength fibre laser.