【Abstract】 A vibrationally excitation spectrum of the A(1A2) ← X(1A1 ) and B(1 B1 )←X(1 A1 ) transition of suifur dioxide (SO2 ) was observed by using the degenerate four-wave laixing (DFWM) technique. For comparison, the direct absorption spectrum of SO2 was also presented. The DFWM signal intensity was investigated as a function of N2 buffer gas pressure. It was found that the signal intensity enhanced 25-fold with the addition of 100 kPa N2 gas.更多还原