Up to date over 4,000 known exoplanets have been detected. Spectroscopy during planet transits in front of host stars is starting to shed light on the diversity of atmospheres and planets. Earth-like rocky planets are intriguing to search for biosignatures such as H₂O, CH₄, O₃ and O₂. Detecting and resolving these very narrow absorption lines from low-pressure atmospheric layers requires extreme spectroscopic resolution, also to distinguish telluric and exoplanet signals. Recent studies indicate upcoming Extremely Large Telescopes combined with spectral resolutions of R~400,000 are ideal to detect O₂ in earth analogs from ground. To boost typical high-resolution spectrographs (R~100,000) to that level, novel Fabry Perot Interferometer-based concepts have been developed. Prototypes achieve a spectral resolution of approximately 500,000 with high throughput. I will present first on-sky results from our prototype and discuss the future of this technology for exoplanet characterization from ground and space.