Derivative Spectroscopy: Enhancing Spectral Features with Meta-Differentiators

Derivative spectroscopy is a technique used to isolate weak spectra from other unwanted interference. It can also enhance the contrast of a weak band compared to a strong overlapped signal in the spectral domain. This technique is widely used for trace analysis, purity tests, and stability tests52,53. However, unlike existing techniques that operate in real space, our meta-differentiators can be used to isolate features in the angular spectrum domain of an object.