Fabrication of micro-lens array using quartz wet etching and polymer

This paper presents the fabrication and test of a micro-lens array (MLA) made of quartz substrate and UV adhesive Numerical analysis of optics was used to find the optimal design parameters such as radius of curvature and etching depth of the micro lens The fabricated device has an array of 1024 x 768 lenses The dimension of each lens is 13 68 mu m x 13 68 mu m A quartz substrate which is a stable material at harsh environment was etched isotropically with buffered oxide etchant (BOE) We found the optimal wet etching time of quartz We spin-coated UV adhesive on quartz substrate to complete the micro-lens array The fill factor was almost 100% The focal length depending on the radius of curvature and thickness of UV adhesive is in the range from 28 1 to 454 mu m The FWHM (full width at half maximum) of the spot size is about 1 5 mu m in case of the sample etched for 95 min at 23 C and 50% absolute humidity Experimental tests demonstrated that each lens is fabricated successfully (c) 2010 Elsevier B V All rights reserved