Fabrication of PDMS (polydimethylsiloxane) microlens and diffuser using replica molding

This paper reports the fabrication method of PDMS (polydimethylsiloxane) microlens array based on the replica molding process, casting a liquid PDMS into concave microlens molds. Concave microlens molds were fabricated through spin-coating processes suspended a liquid PMMA film on the micro-drilled hole, leading to the formation of the special curvature. Then, PDMS microlens arrays and diffusers were fabricated by replica molding and discussed in this study. The fabricated microlenses have both good surface roughness and high-quality optical properties. Therefore, diffusers were fabricated by two-step replica molding. A high-intensity He–Ne laser beam was uniformly spread through diffusers. Experimental tests demonstrated that all PDMS elements are successfully fabricated by replica molding process and operated during optical measurement.