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arXiv · 2206.00839

Ultra-broadband surface-normal coherent optical receiver with nanometallic polarizers

Go Soma·Warakorn Yanwachirakul·Toshiki Miyazaki·Eisaku Kato·Bunta Onodera·Ryota Tanomura·Taichiro Fukui·Shota Ishimura·Masakazu Sugiyama·Yoshiaki Nakano·Takuo Tanemura
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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-{\mu}m-square footprint, we demonstrate demodulation of high-speed (up to 64 Gbaud) coherent signals in various formats. Moreover, ultra-broadband operation from 1260 nm 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.

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Go Soma, Warakorn Yanwachirakul, Toshiki Miyazaki, Eisaku Kato, Bunta Onodera, Ryota Tanomura, Taichiro Fukui, Shota Ishimura, Masakazu Sugiyama, Yoshiaki Nakano, Takuo Tanemura. 2022-06-02. Ultra-broadband surface-normal coherent optical receiver with nanometallic polarizers. https://doi.org/10.1021/acsphotonics.2c00759

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