Fabrication Of Concave And Convex Micro-Optical Elements With Polymer For Free-Space Micro-Optical Bench

The development of micro-optical bench (MOB) technology as so far been limited by its reliance on polysilicon based elements which does not have good optical properties, and does not easily yield the spherical surfaces needed for refracting lenses. Polymers have shown large improvement in the recent years and could be a solution to hasten the development of MOB. We report here on the fabrication using polymers of converging and diverging refracting lens, with diameter ranging between 60 μm and 500 μm and with focal length as small as 100 μm. The polymer investigated where a photosensible cresol novolak (AZ9260), a photosensible epoxy resin (SU8) and a silicone (PDMS). In addition we have developed a phenomenological model and a physical model that elucidate the relationship between the fabrication parameters and the characteristics of the optical elements.