Study On The Raman Spectrum Of Resonance Absorption Using Liquid-Core Optical Fiber

Principle of resonance Raman spectra in liquid-core optical fiber have been studied in the dissertation, resonance Raman spectra of I₂ molecules have been plotted. Using liquid-core optical fiber can enhance the Raman spectra intensity greatly. I₂ in solution is excited by laser of 532nm wavelength, the resonance Raman spectra in the situation of two different densities of 0.012g/L and 0.024g/L, length of 1.2m and 3.2m are obtained. Two new Raman spectral lines of I₂ in benzene solution are found in the experiment which is proved that resonance absorption Raman spectrum by liquid-core optical fiber much stronger than resonance absorption Raman spectrum by absorption tube.Spectra of I₂ in benzene solution shows that Raman scatting light intensity is increased gradually as scattering distance is increased, in the scattering process it is accumulated and it is getting stronger and stronger. At the same time, the absorption in the solution should be considered. So that for a kind of solution and a kind of exciting laser light, there is optimum length of liquid-core optical fiber which made scattering light gets most strong. Using liquid-core optical fiber, or benzene in condition that wavelength of incident laser light is 532nm, the optimum length is 2.5 meters.