Indirect measurement of infrared absorption spectrum through thermal emission of meta-cavity array

Controlling thermal emission is essential for various infrared spectroscopy applications. Metasurfaces can be utilized to control multiple degrees of freedom of thermal emission, enabling the compact thermal emission materials and devices. Infrared spectroscopy such as FTIR (Fourier transform infrared spectroscopy), usually requires external infrared radiation source and complex spectroscopic devices for absorption spectrum measurement, which hinders the implementation of integrated compact and portable measurement equipment. Measuring absorption spectrum through the thermal emission of pixelated thermal emitter array can facilitate the integration and miniaturization of measurement setup, which is highly demanded for on-chip spectroscopy applications. Here, we experimentally demonstrate an integrated technology that allows for indirect measurement of the absorption spectrum through the thermal emission of meta-cavity array. This indirect measurement method opens a new avenue for compact infrared spectroscopy analysis.