Mctamatcrials and mctasurfaccs hold significant promise for space applications due to their compactness and lightweight characteristics. These devices use nanostructures embedded in their flat surfaces to manipulate the electromagnetic field for various purposes. Among their potential applications, metalenses stand out for their prospective role in the next generation of optical instruments deployed in space. Specifically, they offer considerable advantages for free space optical and quantum communications terminals. In intersatellite free space optical communication links, transmitter pointing errors degrade the performance of the link. Nevertheless, optimizing the shape of the transmitted beam through a metalens can improve the communication link performance. In this study, we delve into the application of metalenses for shaping laser beams in intersatellite optical communication scenarios. We present the preliminary design of the metalens and analyze its performance through numerical simulations, analyzing its feasibility and potential in space-based optical communications.

The need of atmospheric information with a higher spatial and temporal resolution drives the development of small satellites and satellite constellations to complement satellite flagship missions. Since optical systems are a main contributor to the satellite size, these are the prime candidate for their miniaturization. We present here a novel optical system where the complete spectrometer part of the optical system is compressed in one flat optical element. The element consists of an array of photonic crystals which is directly placed on a detector. The photonic crystals act as optical filters with a tunable spectral transmission response. From the integrated optical signals per filter and the atmosphere model, greenhouse gas concentrations are obtained using computational inversion. We present in this article the instrument concept, the manufacturing and measurement of the photonic crystals, methods for the filter array optimization, and discuss the predicted retrieval performance for the detection of methane and carbon dioxide.