Fig. 2: Integrated photonic emitters.
From: Integrating planar photonics for multi-beam generation and atomic clock packaging on chip
a Three-stage design for the beam emitter consisting of an evanescent coupler (EVC), meta-grating (MG), and metasurface (MS) with each component contributing to beam shaping and polarization control. b The analogous free-space optics that the PIC and MS devices replace. c The EVC and MG are fabricated in a single silicon nitride device layer and function together as a polarizing beam splitter and a beam expander. Both top-down (bottom) and side (middle) views of the PIC devices are shown. The MS is fabricated on fused silica (top) and can be designed to function as a combination of an optical wedge, lens and waveplate. Polarization is denoted in black
