One-time measurement to characterize complex amplitude single component in symmetry superposed optical vortices

Complex amplitude measurement is an essential prerequisite for light field characterization. In this work, we propose a one-time measurement method to characterize the complex amplitude of symmetry superposed optical vortices (SSOVs) with only one picture registered by CCD. This method includes two strategies we proposed. One is the ring extraction strategy for amplitude measurement, and another is the rotational measurement strategy for phase measurement. In the proof-of-concept experiment, the complex amplitude is characterized, and the mode purity is well measured. This method has excellent flexibility, rapidity, and robustness, which can be applied to various occasions and harsh conditions. Careful alignment and optimized error analysis allow us to generate and measure a single component with mode purity as high as 99.99%.