Large-scale free-space photonic circuits in two dimensions  

作　　者：Maria Gorizia Ammendola Francesco Di Colandrea Lorenzo Marrucci Filippo Cardano 

机构地区：[1]Universitàdegli Studi di Napoli Federico II,Dipartimento di Fisica“Ettore Pancini”,Napoli,Italy [2]Scuola Superiore Meridionale,Napoli,Italy [3]University of Ottawa,Nexus for Quantum Technologies,Ottawa,Ontario,Canada [4]Institute of Applied Science and Intelligent Systems,CNR-ISASI,Pozzuoli,Italy

出　　处：《Advanced Photonics》2025年第1期52-61,共10页先进光子学(英文)

基　　金：supported by PNRR MUR Project No. PE0000023-NQSTI。

摘　　要：Photonic circuits, engineered to couple optical modes according to a specific map, serve as processors for classical and quantum light. The number of components typically scales with that of processed modes, thus correlating system size, circuit complexity, and optical losses. We present a photonic-circuit technology implementing large-scale unitary maps in free space, coupling a single input to hundreds of output modes in a two-dimensional compact layout. The map corresponds to a quantum walk of structured photons, realized through light propagation in three liquid-crystal metasurfaces, having their optic axes artificially patterned. Theoretically, the walk length and the number of connected modes can be arbitrary while keeping losses constant. The patterns can be designed to replicate multiple unitary maps.We also discuss limited reconfigurability by adjusting the overall birefringence and the relative displacement of the optical elements. These results lay the basis for the design of low-loss nonintegrated photonic circuits, primarily for manipulating multiphoton states in quantum regimes.

关 键 词：photonic circuit spin-orbit photonics quantum walks 

分 类 号：O43[机械工程—光学工程]