In a spectrometry setup where a first spectral component dominates a second spectral component having a different wavelength, diffraction of the first spectral component as it passes through the optical train of the spectrometer can produce spectral noise that obscures detection of the second spectral component. To reduce the spectral noise, the light from the spectrometer is subject to spatial filtering or interference such that effects of the first spectral component are removed, or at least reduced. The second spectral component can then be more readily detected by a detector after the spatial filtering or interference. In embodiments, the spatial filtering or interference may be provided by a filtering module, which may be installed in existing spectrometry setups or form part of a unitary spectrometry system.