Measured polarisation (left y-axis) and aperture (right y-axis) efficiencies of the full UdC, INAF, and NAOJ optics including the Si lens (upper, middle, and lower panels, respectively). Aperture efficiencies (orange) for all designs are compliant with the ALMA specification of >80% across full frequency range. Polarisation efficiencies (purple) are mostly compliant with the ALMA specification of >99.5%, with some degradation between 103 and 112 GHz.