Fabrication and characterization of polydimethylsiloxane concave microlens array

Concave microlens array is fabricated with PDMS (polydimethylsiloxane) material. Resist thermal reflow method and reverse pattern replication method are employed to fabricate the concave microlens array. The optical performance of the PDMS concave microlens array is analyzed with ray-trace method. Profile of the PDMS concave microlens array is observed by metallographic microscope and Talystep. It is indicated by the results that the surface profile of the PDMS concave microlens array is clear and distinct. Optical properties are also tested with Beamprofiler system. The shine spots on the focal plane of the microscope objective are of highly uniformity, and essentially coincide well with the simulation result. The PDMS concave microlens array has potential application in many optoelectronic devices, such as diffusers and scanners.

► Fabrication technology has advantages of simple fabrication process and low cost. ► Profiler of the PDMS concave microlens array is clear and distinguishable. ► Shine areas produced by the PDMS concave microlens array are periodic and uniform. ► PDMS concave microlens array is soft so as can be used as curve mcirolens array.