New tiny sensor makes the invisible visible

Phys.org  January 12, 2022 Researchers in the Netherlands developed and demonstrated a different approach to spectral sensing which dramatically simplifies the requirements on the hardware and allows the monolithic integration of the sensors. They used an array of resonant-cavity-enhanced photodetectors, each featuring a distinct spectral response in the 850-1700 nm wavelength range. They showed that prediction models can be built directly using the responses of the photodetectors, despite the presence of multiple broad peaks, releasing the need for spectral reconstruction. They used the sensor to measure the nutritional properties of many materials including milk and to classify different types of plastic. […]