Interleaving metasurface spectrometers to extend the high-quality measurement range

Metasurfaces allow the manipulation of light without the size and weight of traditional optical elements, and offer a path to the type of ultra-compact optical systems needed if optical sensors are to be integrated within manufacturing chains without disrupting them. Here we look at the use of a spatially interleaved metasurface as a method to extend the spectral range over which high-resolution measurements can be obtained with an off-axis metasurface lens. Such a spectrometer exploits chromatic abberation to separate out different wavelengths of light, however the abberation will lead to a degredation in the resolution. By spatially interleaving two such devices the measurement range over which the abberation is minimised can be extended, leading to a more useful device