Laboratory results from an ultra-stable MID IR spectrometer for exo-planet atmosphere characterization.

This article focuses on the development and testing of the MIRASET (Mid-Infrared Absolute Stability Experiment Testbed) program, which aims to achieve ultra-stable flux measurements at the level of a few parts per million (ppm) over hours to days using a Transition-Edge Superconductor (TES) bolometer detector array. Such stability is essential for characterizing atmospheric signatures of terrestrial-sized exoplanets in the habitable zones of nearby K and M stars via mid-infrared spectroscopy (5–15 μm). The study demonstrates that a tungsten filament lamp, monitored by a visible-light photodiode, can provide a stable calibration source, enabling correction for detector gain variations and temperature drifts, resulting in flux stability better than 5 ppm over multi-day observations. Although the current TES array has limited spectral coverage, the results validate the approach for future instruments designed to detect biosignatures and planetary conditions around low-mass stars.