Low Cost, Low Loss Micro-Lens Arrays Fabricated by Soft-Lithography Replication Process

This letter reports on an improved method of fabricating micro-lens arrays using a low-cost replication process. An accurate negative reproduction (stamp) of an existing high-quality lens surface (master) is made by thermally curing Sylgard(R) 182 silicone elastomer (made by Dow Corning(R)) on the master lens surface. Fabricating the stamp on a rigid backing plate minimizes distortion of the replica surface. Dispensing silica nanoparticle loaded liquid epoxy (Polyset PCX 2891B) into the mold and curing it under UV radiation on a quartz substrate generates a replica lens array. Loading the epoxy with nanoparticle silica increases the hardness of the replicated lens and reduces its organic content, which in turn reduces the intrinsic optical loss.