Miniaturized dual-photodiode sensor for simultaneous wavelength and irradiance measurement across the 500–1000  nm range

Abstract

We introduce what we believe to be a novel chip-scale dual-photodiode sensor capable of simultaneously measuring centroid wavelength and irradiance within the 500–1000 nm range. The sensor employs a dual-photodiode design, where one photodiode is equipped with a coated filter layer to create differential responsivity, allowing for accurate spectral and intensity detection. Our sensor demonstrates high accuracy, with centroid wavelength and intensity measurements within a 5% margin of error for light sources with a full width at half maximum (FWHM) of 50 nm. This design supports the use of optional optical filters tailored to specific wavelength ranges, enhancing adaptability across diverse applications. Experimental validation confirms its practical potential in a variety of fields, including precision agriculture, horticulture, and environmental monitoring, especially for studies involving far-red and near-infrared light sources. The chip-scale fabrication of the sensor ensures cost-effective, portable, and scalable deployment, positioning it as a versatile solution for advancing optical sensing technologies in various scientific and industrial fields.