Monolithically Integrated 40-Wavelength Demultiplexer and Photodetector Array on Silicon

Abstract

We demonstrated a 40-channel dense-wavelength-division-multiplexed (DWDM) monolithically integrated receiver on silicon, which consists of a silicon nitride <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(\hbox{Si}_{3}\hbox{N}_{4})$</tex> </formula> arrayed waveguide grating (AWG) demultiplexer with integrated germanium-on-silicon waveguide photodetectors. Net responsivities from a cleaved standard single-mode fiber to detectors of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$0.15\sim 0.22$</tex></formula> A/W are measured, with flattened passbands with 1-dB bandwidth over 60% of the 200-GHz channel spacing. Single-channel operation up to 40 Gb/s is demonstrated with a SiGe transimpedance amplifier.