A silica micro-lens has been proposed which can be integrated with planar optical waveguide circuits. The lens pair enables an optical signal to travel in free space between two opposing planar waveguides with minimal optical loss. Each lens pair consists of a slab GRIN lens with a convexly shaped front face. This paper brieftly reviews the micro-lens design process and reports progress in fabircating the device. The characterisation of the GRIN layer and masking experiments used to evaluate the deep oxide etch are presented. A selectivity of 250:1 was achieved for the deep oxide etch using a NiCr mask.