High fill factor microlens array fabrication using direct laser writing and its application in wavefront detection

We fabricate 100% fill factor microlens arrays (MLAs) using femtosecond laser direct writing. The array consists of periodical hexagonal plano-convex microlens units with a diameter of 9 µm. The focusing efficiency of each microlens is measured to be 92%. Combined with a CCD camera, the MLA works as a Shack-Hartmann wavefront sensor. We use it to detect wavefronts of both oblique incident plane beams and vortex beams. The experimental results match well with theoretical ones.