Fig. 1. Transverse field distribution of Gaussian beam

Fig. 2. Gaussian beam

Fig. 3. Transformation of Gaussian beam

Fig. 4. Geometric coordinate system for calculation of fringe spacing distribution

Fig. 5. Schematic of light path for double beam pattern LDV

Fig. 6. Experiment site layout

Fig. 7. 2D figure for beam profile

Fig. 8. Variation diagram of the beam diameter. (a) Green beam; (b) purple beam

Fig. 9. Fringe spacing and gradient distribution. (a) Green beam; (b) purple beam

Fig. 10. Principle diagram of measuring fringe spacing of spinning-disk system