A Miniaturized MEMS-based Spectrometer for Lunar In-Situ Exploration

Kurzfassung

Rock-forming minerals exhibit diagnostic spectral features in the mid- and long-wavelength infrared range, enabling in-situ compositional analysis. For example, silicates show a characteristic Christiansen feature between 7.5 and 9 µm, with Reststrahlen bands and transparency features located between 9 and 13 µm. Consequently, spectral coverage from approximately 7.5 to 13 µm allows extensive mineralogical and compositional characterization of planetary materials. Mineralogical features in this wavelength range are typically broad (>0.5 µm), resulting in moderate spectral resolution requirements that can be addressed using MEMS-based Fabry-Pérot interferometers. When operated in the first interference order, these filters provide free spectral ranges of a few micrometers with spectral resolutions λ/Δλ around 50, sufficient to resolve diagnostic mineral features. MEMS Fabry-Pérot technology offers compact size, high optical throughput, and electrical tunability, making it well suited for miniaturized space instrumentation.