Fig. 1. Scattering spectrum of interaction between laser and sea water

Fig. 2. Diagram of Brillouin lidar system diagram

Fig. 3. Experimental setup for measuring Brillouin scattering in water with scanning F-P interferometer

Fig. 4. Brillouin scattering spectrum measured in water

Fig. 5. Principle of Brillouin scattering measurement in water using edge technology

Fig. 6. (a) Absorption lines of bromine; (b) Absorption lines of iodine

Fig. 7. (a) Dependence of normalized intensity signal on temperature; (b) Dependence of normalized intensity signal on Brillouin shift after calibration

Fig. 8. Experimental setup of lidar system using ESFADOF as edge detection technology. (a) Laser source generation scheme; (b) Laser scattering scheme and corresponding Brillouin scattering spectrum line; (c) Edge detection scheme and corresponding edge filtering curve

Fig. 9. [in Chinese]

Fig. 9. (a1) Comparison of the temperature results measured by two lidar tubes and Pt100 after 50 000 measurements, (a2) Error analysis; (b) Relationship between the average temperature deviation, average number and acquisition duration of two lidar tubes

Fig. 10. (a) Sketch of underwater Brillouin lidar system using F-P etalon combined with ICCD; (b) Principle of spectrum detection using F-P etalon combined with ICCD

Fig. 11. Flow chart of underwater Brillouin scattering detection system

Fig. 12. Double edge technique used in Brillouin scattering spectrum.(a) Principle of double edge filtering technique; (b) Sketch of experimental device of double edge filtering method