[Study on the nonlinear Raman lidar monitoring the CO2 gas]

It is a new skill to use SRS rays as emitting waves for the lidar monitoring CO2 gas, and the nonlinear Raman lidar based on the SRS process was devised. The third harmonic Nd: YAG laser wave (354.7 nm) was injected into the Raman cells filled with higher pressure gases, CO2 and N2. The first Stokes (S1) line 371.66 nm (CO2) and 386.7 nm (N2) were generated by stimulated Raman scattering. The variable S1 energy was measured by changing the gas pressure in the Raman cell andthe Nd:YAG laser system output energy. The optimum pressures of the CO2 and N2 in the Raman cell were achieved. Moreover, the principles of this physical process were put forward. This skill has been applied to the lidar for monitoring the CO2 gas.