Dispersive silicon-nitride optical phased array incorporating arrayed waveguide delay lines for passive line beam scanning.

As optical phased arrays (OPAs), used as solid-state beam scanning elements, swiftly stride towards higher efficiency and faster scanning speed, the line beam scanner is emerging as a viable substitute for its counterpart relying on point-beam-incorporated raster scanning. However, line-beam scanners require active phase shifters for beam scanning; thus, they consume more power and have complex device designs. This study proposes and demonstrates a dispersive silicon-nitride OPA that allows for passive wavelength-tuned steering of a line beam with an elongated vertical beamwidth.

Flat optical phased array receiver incorporating an on-chip metalens concentrator.

We propose and design a flat optical phased array (OPA) receiver that consists of a grating antenna, a free-propagation region (FPR) incorporating an on-chip metalens concentrator (OCMC), and an output port of a tapered waveguide. By concatenating the OCMC-integrated FPR with the antenna, the proposed OPA allows light coupled at a slanted ψ angle to be conveyed to the output, thereby resolving the challenges of phase-controlled light detection. To impose a space-dependent phase on the incident light from the antenna, the OCMC is constructed by laterally arranging subwavelength slot meta-atoms with varying slot lengths, which are created in the core layer of a slab and uniformly quantized at 16 phase levels.