Dual Band Computational Infrared Spectroscopy via Large Aperture Meta-Optics

An important challenge in contemporary photonics research is the miniaturization of optical components and devices to facilitate their deployment in more compact and energy-efficient mobile platforms. As spectrometers are one of the most essential tools for optical measurements, a particularly strong demand exists to find new concepts to replace commonly used spectrometers, which are typically bulky and therefore often impractical for mobile applications. Arrays of subwavelength scatterers, also known as meta-optics, engineered to shape and manipulate transmitted optical wavefronts provide a particularly appealing solution for this problem. Herein, the concept of a computational spectrometer is presented where strongly chromatic point spread functions of a high-efficiency double helix meta-optic are utilized in combination with a computational back end to accurately reconstruct optical spectra. This is demonstrated in two different infrared wavelength ranges (1260–1360 nm and 1480–1640 nm), while achieving a spectral resolution of ∼3.5 nm, underlining the potential of a small footprint meta-optical spectrometer.