A monolithic integrated plasmonic Schottky photodetector array for direct-detected miniaturized spectrometers

Computational spectroscopy combined with small chip-level spectrometer is crucial in achieving high-precision miniature spectrometers. One noteworthy scheme arising from computational spectroscopy is the plasmonic Schottky photodetector, which offers advantages such as monolithic integration, no filter, and CMOS compatibility. In this research, we report a spectral analysis based on a monolithic integrated plasmonic Schottky detector array. We integrate different structures on a 5mm*5mm detector by electron-beam lithography (EBL) method, and obtain a set of response curves with low correlation by adjusting the parameters of shape, period and width. Within the operational wavelength range of 450-950 nm, our fabricated detector demonstrated a low average correlation coefficient of 0.531 among its 16 individual pixels. Furthermore, we successfully validated the spectral recovery capabilities of this detector using deep neural network, achieving a spectral recovery resolution of 10 nm. These findings demonstrated the feasibility of realizing miniaturized spectrometer with plasmonic Schottky photodetector array.