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

作　　者：Zhongzheng Lin Jianqi Hu Yujie Chen Camille-Sophie Bres Siyuan Yu 

机构地区：[1]Sun Yat-sen University,School of Electronics and Information Technology,State Key Laboratory of Optoelectronic Materials and Technologies,Guangzhou,China [2]Ecole Polytechnique Fédérale de Lausanne,Photonic Systems Laboratory,STI-IEM,Lausanne,Switzerland

出　　处：《Advanced Photonics》2023年第3期135-143,共9页先进光子学（英文）

基　　金：supported by the National Key Research and Development Program of China (2018YFB1801803, 2019YFA0706302);the Basic and Applied Basic Research Foundation of Guangdong Province (2021B1515020093, 2021B1515120057);the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01X121);the Swiss National Science Foundation (P2ELP2_199825)

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

关 键 词：orbital angular momentum Kramers-Kronig relations single-shot measurement phase retrieval 

分 类 号：O43[机械工程—光学工程]