Polymer Waveguide Co-integration with Microelectromechanical Systems (MEMS) for Integrated Optical Metrology

The merging of Microelectromechanical (MEM) devices and optics to create Microoptoelectromechanical (MOEM) systems provides opportunity to create new devices and to expand the functionality and applications of MEMS technology. Planar optical waveguide co-integration with surface micromachined (SMM) structures and inclusion of diffractive optical systems within 3-D MEMS chip stack architectures have the potential to enable integrated optical test, metrology, and state feedback functions for complex MEM systems. This paper presents the results of research developing a fabrication process for co-integrating polymer optical waveguides with prefabricated MEMS devices. Multimode air superstrate rectangular optical waveguides have been fabricated using Ultradel optical polyimides over unreleased MEMS dice fabricated using the MultiUser MEMS Process Service (MUMPS) SMM process. These structures serve as the basic building block for exploration of guided wave integrated optical metrology functions for MEMS. Specially designed "split-comb" linear resonator devices enabling coupling of waveguide output to the resonator stage for position measurement are one class of a set of prototype vIEMS function MUMPS testbeds under development for both guidance and evaluation of waveguide and free-space TOM efforts. Recently initiated work analytically and experimentally evaluating through-wafer free-space micro-optical systems for TOM will also be outlined.'