Tunable hyperchromatic microlens array for compact 2D spectrometry

We present a new concept for highly-miniaturized spectrometry based on a 5×5 array of tunable hyperchromatic microlenses (HML) which can be used for two-dimensional spatial mapping of spectral data in chemical reaction chambers. Each individual HML consists of a diffractive Fresnel lens combined with a tunable liquid microlens with high spectral dispersion as well as tunable focal length, forming a hyperchromatic element. Each element performs as an ultracompact spectrometer with a spectral resolution of 32 nm. The transmission spectrum of Bromophenol blue solution is measured using the HML array to demonstrate its applicability to chemical analysis.