Stimulated Raman Stokes scattering influenced by all-trans-β -carotene in liquid-core optical fiber

We demonstrate stimulated Raman Stokes (SRS) scattering of carbon disulfide (CS 2 ) influenced by a natural dye named all- trans -β-carotene in a liquid-core optical fiber (LCOF). These Stokes emissions can acquire the extra effects of seeding or suppression, both of which result from the optical properties of the carotenoids. Then, the efficient control of the selective developments of the Stokes lines by the natural dyes is available in LCOFs. Especially, the low threshold of the high-order Stokes lines, such as the 2nd Stokes line of CS 2 , can be more easily obtained through the seeding effect. The saturation intensity of the 1st Stokes line can be suppressed more when the concentration of all- trans -β-carotene in CS 2 becomes high. Simultaneously, the threshold of the 1st Stokes line increases with the addition of the carotenoids. This result is expected to be worthy of new SRS-based fiber light sources for bio-medicine applications such as photodynamic therapy.