Mitigating transmission sidelobes in NIR Liquid Crystal Tuneable Filters using inverse methods

Popular Near Infrared Liquid Crystal Tuneable Filters possess anomalous transmission sidelobes at a subset of tuneable wavelengths. This violates the assumption that these devices have a narrow bandpass characteristic and complicates attempts to infer general reflectance spectra. We present an inverse method to recover material reflectance even in the presence of these unwanted sidelobes. Experimental results show that the proposed solution is much more accurate at recovering material reflectance than more common approaches, reducing the reconstruction error (normalised maximum difference) for the considered material by 40%.