Monolithic high-contrast metastructure for beam-shaping VCSELs

We report a high-contrast metastructure (HCM) mirror as a novel beam-shaping element for vertical-cavity surface-emitting lasers (VCSELs). The metastructure is monolithically integrated as a part of the VCSEL, working both as a microelectromechanical tunable mirror and output beam shaper. While providing broadband, high reflection to support lasing of the VCSEL, its angular transmission characteristics can be tailored to shape the angular profile of the output beam. Various far-field emission patterns are demonstrated for single-mode, 1550 nm VCSELs with different HCM designs. We further demonstrated two-faced VCSELs with different mode profiles from their two mirrors, for the first time, to the best of our knowledge. This bifunctional integrated metastructure opens new avenues to engineer a VCSEL’s emission properties, and shows great promise for applications that desire highly compact emitters integrated on a chip to provide versatile functionalities.