Fabrication of polymer-based optical microsystem arrays suited for the active focusing of vertical laser diodes

We present a low-cost fabrication technique of a polymer-based micro-optical-electrical-mechanical systems (MOEMS) suited for the dynamic focusing of VCSELs (vertical-cavity surface-emitting lasers). A simple method based on an SU(8) double exposure is proposed for the collective integration of small footprint transparent suspended membrane arrays on vertical laser diodes. We demonstrate that this kind of MOEMS can provide under thermal actuation a vertical displacement of around 0.2 µm W⁻¹ over a maximal range of 8 µm. As a wide range of initial gaps between the membrane and the laser source can be chosen, this approach opens new insights into the dynamic control of the VCSEL beam waist position as well as for tunable VCSEL fabrication. (paper)