High-angle deflection of metagrating-integrated laser emission for high-contrast microscopy  

作　　者：Mindaugas Juodėnas Erik Strandberg Alexander Grabowski Johan Gustavsson HanaŠípová-Jungová Anders Larsson Mikael Käll 

机构地区：[1]Department of Physics,Chalmers University of Technology,41296 Gothenburg,Sweden [2]Department of Microtechnology and Nanoscience,Chalmers University of Technology,41296 Gothenburg,Sweden

出　　处：《Light(Science & Applications)》2023年第11期2434-2442,共9页光（科学与应用)（英文版）

基　　金：This work was funded by the Knut and Alice Wallenberg Foundation and performed in part at Myfab Chalmers.The authors acknowledge Emelie Tornéus for assistance preparing the cell samples and Ruggero Verre for assistance with the nanofabrication.Cell samples were a kind gift from Caroline Adiels.Nanorods were synthesized by Lei Shao.

摘　　要：Flat metaoptics components are looking to replace classical optics elements and could lead to extremely compact biophotonics devices if integrated with on-chip light sources and detectors.However,using metasurfaces to shape light into wide angular range wavefronts with high efficiency,as is typically required in high-contrast microscopy applications,remains a challenge.Here we demonstrate curved GaAs metagratings integrated on vertical-cavity surface-emitting lasers(VCSELs)that enable on-chip illumination in total internal reflection and dark field microscopy.Based on an unconventional design that circumvents the aspect ratio dependent etching problems in monolithic integration,we demonstrate off-axis emission centred at 60°in air and 63°in glass with>90%and>70%relative deflection efficiency,respectively.The resulting laser beam is collimated out-of-plane but maintains Gaussian divergence in-plane,resulting in a long and narrow illumination area.We show that metagrating-integrated VCSELs of different kinds can be combined to enable rapid switching between dark-field and total internal reflection illumination.Our approach provides a versatile illumination solution for high-contrast imaging that is compatible with conventional microscopy setups and can be integrated with biophotonics devices,such as portable microscopy,NIR-II range bioimaging,and lab-on-a-chip devices.

关 键 词：ILLUMINATION DEFLECTION OPTICS 

分 类 号：TN24[电子电信—物理电子学]