Influence of amplified spontaneous emission and fluorescence of β-carotene on stimulated Raman scattering of carbon disulfide

Abstract

β-carotene with double fluorescence characteristics and large third-order optical nonlinearities, which is dissolved in the carbon disulfide (CS2) as the core medium of a liquid core optical fiber (LCOF), is applied in the study of the CS2 stimulated Raman scattering (SRS). The results of this study show that when the concentrations of solution are more than 3.72×10−7 mol/L, the amplified spontaneous emission (ASE) of β-carotene is the main factor influencing the threshold and intensity of Stokes lines; when the concentrations of solution are lower than 3.72×10−7 mol/L, the ASE disappears and the fluorescence plays the key role: The high-order Stokes lines may be observed at very low input-laser power, and the Stokes thresholds decrease as the solution concentration increases. The result may be widely used in the study of broadband stimulated radiation laser and seeding laser.