title: Integrated compact optical vortex beam emitters.
abstract: Emerging applications based on optical beams carrying orbital angular momentum (OAM) will probably require photonic integrated devices and circuits for miniaturization, improved performance, and enhanced functionality. We demonstrate silicon-integrated optical vortex emitters, using angular gratings to extract light confined in whispering gallery modes with high OAM into free-space beams with well-controlled amounts of OAM. The smallest device has a radius of 3.9 micrometers. Experimental characterization confirms the theoretical prediction that the emitted beams carry exactly defined and adjustable OAM. Fabrication of integrated arrays and demonstration of simultaneous emission of multiple identical optical vortices provide the potential for large-scale integration of optical vortex emitters on complementary metal-oxide-semiconductor compatible silicon chips for wide-ranging applications.
authors.affiliation: Photonics Group, Merchant Venturers School of Engineering, University of Bristol, Bristol, UK.
authors.forename: Xinlun
authors.initials: X
authors.lastname: Cai
authors.forename: Jianwei
authors.initials: J
authors.lastname: Wang
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Strain
authors.forename: Benjamin
authors.initials: B
authors.lastname: Johnson-Morris
authors.forename: Jiangbo
authors.initials: J
authors.lastname: Zhu
authors.forename: Marc
authors.initials: M
authors.lastname: Sorel
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: O'Brien
authors.forename: Mark G
authors.initials: MG
authors.lastname: Thompson
authors.forename: Siyuan
authors.initials: S
authors.lastname: Yu