Fig. 1. Flow chart of the data acquisition system

Fig. 2. Optical path diagram of OPO system

Fig. 3. Front panel of data acquisition system

Fig. 4. Setting of channel parameters

Fig. 5. Setting of trigger parameters

Fig. 6. Setting of acquisition parameters

Fig. 7. Control module of OPO system

Fig. 8. Module of signal processing

Fig. 9. Flow chart of signal processing

Fig. 10. Original signal

Fig. 11. Processed signal

Fig. 12. Resolution comparison

Fig. 13. Comparison of sampling points

Fig. 14. Infrared absorption spectrum