A system of two solid microlenses with uncoupled optical properties is presented. This structure has been designed in order to have one lens as a reference, while the other one can be mechanically tuneable. The reference lens presents a diameter of 2 μm and it is placed in the optical axis of the mechanically tuneable lens, which has a diameter of 10 μm. The proposed microoptical structure has been fabricated in poly(dimethilsiloxane) (PDMS) merging deep reactive ion etching, SU-8 and soft lithography, with a low-cost (mass-production), simple and highly repetitive technology. This device was numerically simulated prior to its fabrication, to optimize its design and improve its behaviour. In addition, an optical characterization of the fabricated devices was carried out. Both simulation and experimental results shows a good agreement, under mechanical actuation behaviour of the reference lens is invariable, while the tuneable lens become an elliptic lens and the interval of Sturm can be observed. These results provide a proof of concept of the proposed devices and validate both the design and the fabrication technology.
- Tuneable focus