Grating – Resonance InGaAs Narrowband Photodetector for Multispectral Detection in NIR – SWIR Region

We proposed grating-resonance narrowband photodetector (PD) for the wavelength selection functionality at the wavelength of $1300 \sim 1700$ nm. We first carefully designed the PD using the device structure of InGaAs thin absorbing layer formed on Si grating for the optical resonance, providing narrowband detection at specific wavelength. Based on parameters designed from the simulation, we fabricated an array of pixels to selectively detect different wavelengths, but with the same PD thickness across the whole pixels. Then, we systematically characterized the fabricated narrowband PDs. Our device showed great wavelength selectivity and tunability depending on the grating design with a quite narrow full width half maximum $\lt 26$ nm.