Ultra-thick micro-optical components using the PRISM photosensitive flexopolymer
We present the photosensitive flexopolymer PRISM as a new promising material for the realization of thick optical components. The PRISM flexopolymer can be directly polymerized using conventional UV exposure and is simply developed in a water-based solution. A casting method is used to realize flexopolymer layers of a few millimetres thickness in a single application step. Optical components as thick as 2 mm have been fabricated using an exposure time of less than 1 min and a development time below 3 min. No baking process is required, making the process very fast and avoiding any temperature-induced stress problems. Due to its elastomeric nature, the material can be easily applied either on rigid or flexible supports. The good optical transmission of the PRISM flexopolymer in the 400–800 nm spectral range makes it a promising material for optical applications. Refractive index measurements are performed at different wavelengths in the UV–visible range and the flexopolymer refractive index dispersion behaviour is determined. Optical components such as right-angle prisms, penta-prisms and cylindrical lenses with thicknesses up to a few mm have been successfully fabricated.