'工学部/工学系研究科 プレスリリース' blog (64135473799) of hub id 20511701

PRESS RELEASE

Ultra-Broadband Surface-Normal Coherent Optical Receiver with Nanometallic Polarizers


Authors

Go Soma, Warakorn Yanwachirakul, Toshiki Miyazaki, Eisaku Kato, Bunta Onodera, Ryota Tanomura, Taichiro Fukui, Shota Ishimura, Masakazu Sugiyama, Yoshiaki Nakano, and Takuo Tanemura


Abstract
A coherent receiver that can demodulate high-speed in-phase and quadrature signals of light is an essential component for optical communication, interconnects, imaging, and computing. Conventional waveguide-based coherent receivers, however, exhibit large footprints, difficulty in coupling a large number of spatial channels efficiently, and limited operating bandwidth imposed by the waveguide-based optical hybrid. Here, we present a surface-normal coherent receiver with nanometallic-grating-based polarizers integrated directly on top of photodetectors without the need for an optical hybrid circuit. Using a fabricated device with the active section occupying a 70-μm-square footprint, we demonstrate demodulation of high-speed (up to 64 Gbaud) coherent signals in various formats. Moreover, ultra-broadband operation from 1260 to 1630 nm is demonstrated, thanks to the wavelength-insensitive nanometallic polarizers. To our knowledge, this is the first demonstration of a surface-normal homodyne optical receiver, which can easily be scaled to a compact two-dimensional arrayed device to receive highly parallelized coherent signals.

fig1e


ACS Photonics: https://pubs.acs.org/doi/10.1021/acsphotonics.2c00759