The wave-particle duality of light manifested in spectrometer designs

It has been known for 100 years that light is both a wave and a particle, yet our approach to measuring light spectrum is still rooted only in the wave nature of light. Spectrometers built in this way suffer from the compromise between spectral features and device sizes. Recently, a particle-based spectrum detection method, coupled with advanced algorithms, has emerged. These new spectrometers offer high spectral resolution, wide spectral range, as well as compact size. This review outlines the principles, implementation, characteristics, performance, and extension of both wave and particle-based spectral detection technologies.