Experimental study on enhancing rotational velocity measurement performance based on a phase retrieval algorithm

Due to its unique spiral wavefront structure and orbital angular momentum (OAM) properties, vortex beams have demonstrated exceptional potential for rotational velocity measurement applications leveraging the rotational Doppler effect. However, during remote sensing applications, atmospheric turbulence-induced distortion and the resulting increase in velocity measurement errors pose significant obstacles to their practical use. Phase compensation offers a promising approach to address this issue. This study experimentally validates the effectiveness of Gerchberg-Saxton (GS) algorithm phase compensation in restoring the optical field and reducing velocity measurement errors. The influence of key factors, such as turbulence intensity, GS algorithm iterations, OAM modes, and sampling duration, on velocity measurement performance is analyzed. Experimental results demonstrate that the distortion and spatial overlap of petal-shaped spots can be effectively restored through the GS algorithm compensation. Optimizing the number of GS iterations, OAM mode, and sampling time can help alleviate the impact of turbulence on the key velocity measurement performance metrics. This research provides experimental evidence for demonstrating the practical application potential of adaptive optical algorithms in remote velocity measurement.