Fig. 1. Geometric diagram of interference from a set of coherent light sources

Fig. 2. Principle of phase difference integration of light through an axisymmetric refractive index field

Fig. 3. Diagram of the effect of slits on stripes

Fig. 4. Comparison of the light intensity corresponding to different widths of double slit diffraction

Fig. 5. Interference fringe optical range difference of different imaging planes

Fig. 6. Interference fringe optical range difference of different imaging planes

Fig. 7. Interference fringe optical path difference of different flame positions

Fig. 8. Interference fringe offsets for different flame positions

Fig. 9. Numerical simulation

Fig. 10. Interference fringe offsets for different flame temperatures

Fig. 11. Comparison of calculation results at different center temperatures

Fig. 12. Variation curve of maximum value of stripe deflection with center temperature

Fig. 13. Experimental system diagram

Fig. 14. Interference stripe pattern

Fig. 15. Grayscale distribution of interfering stripes

Fig. 16. Offset of interference stripes

Fig. 17. Reconstruction of temperature field by flame of alcohol lamp

Fig. 18. Background-Oriented Schlieren （BOS） system scene map

Fig. 19. Alcohol lamp flame reconstruction results graph