Miniaturized high-NA blue objective

In order to enable optical storage in portable devices, a small optical drive building height and thus small sized objectives are needed. A small version of the DVR objective, having numerical aperture of 0.85 and operating wavelength (lambda) = 405 nm is required, in order to have sufficient storage capacity on a small sized disc. In this paper we present a miniaturised DVR objective made of plastic. It has a building height of only 1.335 mm, enabling optical storage for various mobile applications. Making the objective out of plastic eases the manufacturing and handling. Furthermore, the two element objective was designed to have low temperature dependence which was confirmed experimentally. Experiments with this objective showed that readout of a 25 GB RW 12 cm disc is possible. Furthermore, some considerations on the benefits and expected problems in miniaturizing the actuator are presented.