We report for the first time a UV curable polymer with effective optical transmission below 300 nm. Through careful control of kinetics, various viscosities can be generated to optimize the film forming properties via spin coating. The transmission of the monomers and films is investigated over a spectral range which spans the 240-370 nm output of ultraviolet AlInGaN light-emitting diodes. The refractive index of the polymer has been measured by ellipsometry to give a value of 1.57 at 280 nm. Using standard lithography techniques with reactive ion etching, arrays of microlenses have been fabricated in this polymer with diameters of 30 νm and below and are characterized by atomic force microscopy and confocal microscopy. © 2008 IOP Publishing Ltd.