Design, fabrication and characterization of solution-based molded chalcogenide optics for infrared application

We report design, fabrication and characterization of molded chalcogenide microlens array for Infrared sensing applications. A master of desired microlens array with high sag value is prepared using ultraviolet lithography and thermal reflow method on a positive photoresist (ma–P1275HV). The negative replica of the master is created using polydimethylsiloxane which serves as a mold for micro-molding. Further, chalcogenide solution is prepared in ethanolamine solvent and spin coated on a substrate to get a uniform film; these films are characterized and are found to have the same optical properties as the parent bulk chalcogenide glass. Finally, the microlens array is fabricated by the micro-molding of chalcogenide film. Fabricated chalcogenide microlenses are characterized for geometrical parameters, which are used to estimate the optical parameters.