Research On Pump-probe And Four-wave Mixing Based-on Surface Plasmon Polaritons

Recently, the investigation of molecular ultrafast dynamics using femtosecond(fs) pump-probe technique attracts great attention. The application of surface Plasmonpolariton (SPP) and long range surface Plasmon polariton (LRSPP) in fs pump-probetechnology can improve the accurateness of molecular relaxation dynamics, theapplication of LRSPP in four wave mixing will be able to improve the conversionefficiency. In this dissertation, fs pump-probe technique based on SPP and LRSPP,and four wave mixing process based on LRSPP were simulated numerically.Firstly, we investigate numerically the stimulating condition of SPP, thecondition of SPP-based pump-probe, and the change of the condition of stimulatingthe SPP and SPP-based pump-probe with different detecting wavelength and metalfilm thickness. We compare the variation of relative reflectivity between theSPP-based pump-probe and standard pump-probe. In addition, we analyze the reasonfor the change using the two-temperature model and energy level transition theory.Secondly, we simulate the stimulating condition of LRSPP and LRSPP-basedpump-probe, and the change of the condition of stimulating the LRSPP andLRSPP-based pump-probe with different detecting wavelength and metal filmthickness. Also we compare the variation of relative reflectivity between theLRSPP-base pump-probe, SPP-base pump-probe and standard pump-probe.Finally, LRSPP was used as pumped beam to realize four-wave mixing. simulateAnd We simulate the relationship between the input light wavelength and incidentangle in the LRSPP-based four-wave mixing process, as well as the relationshipbetween the angle of output light and the input light wavelength when the excitationwavelength is fixed. When the input light wavelength is different, we simulate therelationship between input light wavelength, incident angle and output light angle,analyzing the variation under this condition.