Polarization‐Resolved Remote Velocimetry Using Vector Incoherent Rotational Doppler Effect

The rotational Doppler effect (RDE) presents a promising approach for molecular spinning observation, ghost imaging, nonlinear optical characterization, detection of object‐rotational axis orientation, perception of object symmetry, and other advanced photonic technologies. However, simultaneous measurement of angular velocity and polarization characteristics under practical outdoor misalignment conditions remains challenging. Here, we demonstrate a vector incoherent RDE‐based system enabling concurrent off‐axis rotational velocimetry and polarimetric sensing in practical environments. It utilizes vector incoherent illumination with a post‐modulation system to achieve off‐axis velocimetry. The periodic changes in coherence structures of the echo signal generate a frequency peak related to the rotational speed, enabling an off‐axis measurement precision better than 0.001 r s − 1 . The combination of the circularly polarized light source and a rotating linear polarizer generates polarization‐dependent intensity modulations. Experimental results confirm the system's ability to simultaneously resolve rotational speed and polarization states under outdoor conditions without stringent co‐alignment requirements. This work establishes a practical framework for remote sensors capable of decoding off‐axis rotational dynamics and polarization properties.