Programmable manufacturing technique of long-focal-length microlens arrays

Long-focal-length microlens arrays is one of the main components of the Shack- Hartmann type wavefront sensor. For an application in astronomy we have developed a specific microlens manufacturing process based on photolithographic techniques. At first, in this paper, we briefly report on the procedure and we highlight the programmable possibilities according to scientific and technical specifications. Secondly, we describe the different studies we have worked out to improve the technique and determine its limitations. Finally, the results of mechanical and optical tests are compared with computing simulations in order to qualify the microlens arrays manufactured through this technique. In conclusion, the technique we have developed in our laboratory is fast and reliable; the microlenses manufactured with this procedure are diffraction-limited. This photolithographic technique is easy to transfer to an industrial manufacturing environment, each step of the process being programmable.