Fig. 1. Skew angle between Poynting vector and its optical axis

Fig. 2. Deviation between the optical axis and the spinning center

Fig. 3. |1 +|4 Superposed Bessel-Gaussian beams detecting spinning object |1 +|4 的叠加态的贝塞尔高斯光束对旋转物体探测

Fig. 4. Vortex beams detect a spinning object with linear velocity

Fig. 5. Vortex beams detect the Doppler effect caused by complex motion

Fig. 6. Beat frequency in multi-OAM mode vortex beam detection compound motion

Fig. 7. Motion of object portrayed by superposed vortex beams

Fig. 8. Doppler effect caused by transverse motion