CSEM in Switzerland is currently designing and implementing an alternative detector prototype. The initial spectrometer with the VIPA is showing adequate resolution to resolve the fine structure of N2O gas spectral footprint. However, it appeared that the detection limit is currently 2 orders of magnitude too high to measure diluted samples as requested in the FLAIR project. The revised design promises reduced optical losses and larger power per spectral unit achieved through lowering the resolution. "We are now aiming at detecting the envelope of gas species, or gases with broader absorption lines, like e.g. methane. We are starting the fabrication and testing of this new 2D spectrometer prototype." - says Julien Gouman, R&D Engineer for the FLAIR project at CSEM.