Single-shot Kramers–Kronig complex orbital angular momentum spectrum retrieval

Orbital angular momentum (OAM) spectrum diagnosis is a fundamental building block for diverse OAM-based systems. Among others, the simple on-axis interferometric measurement can retrieve amplitude and phase information of complex OAM spectra in few shots. Yet, its single-shot retrieval remains elusive, due to signal–signal beat interference inherent measurement. Here, we introduce concept Kramers–Kronig (KK) receiver coherent communications domain, enabling rigorous, We explain detail working principle requirement KK method then apply technique precisely measure various characteristic states. In addition, discuss effects carrier-to-signal power ratio number sampling points essential rigorous evaluate performance on large set random high-dimensional spaces. Single-shot interferometry shows enormous potential characterizing states real time.