Wavelength Modulation of Differential Absorption lidar for CO_2 Detection

In order to get precise wavelength on detecting co2,the output wavelength of differential absorption lidar system must be stabilized and modulated on 1571.276nm which is one of absorption peak on co2 by using detector,co2 gas cells and lock-in amplifier based on the theory of FM spectroscopy.Through the medium of test,we can tune the wavelength smoothly with sub-angstrom precision and even have got much better stabilization.