Ultra-compact broadband polarization diversity orbital angular momentum generator with 3.6 × 3.6 μm² footprint.

ABSTRACT: Orbital angular momentum (OAM), one fundamental property of light, has been of great interest over the past decades. An ideal OAM generator, fully compatible with existing physical dimensions (wavelength and polarization) of light, would offer the distinct features of broadband, polarization diversity, and ultra-compact footprint. Here, we propose, design, fabricate, and demonstrate an ultra-compact chip-scale broadband polarization diversity OAM generator on a silicon platform with a 3.6 × 3.6 μm² footprint. The silicon OAM chip is formed by introducing a subwavelength surface structure (superposed holographic fork gratings) on top of a silicon waveguide, coupling the in-plane waveguide mode to the out-plane free-space OAM mode. We demonstrate in theory and experiment the broad

SUBMITTER: Zhou N 

PROVIDER: S-EPMC6544453 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature