AVS 52nd International Symposium
    MEMS and NEMS Tuesday Sessions
       Session MN-TuM

Paper MN-TuM4
Monolithic In-Plane Tunable Optical Filter

Tuesday, November 1, 2005, 9:20 am, Room 207

Session: Micro and Nano Fabrication Techniques for MEMS & NEMS
Presenter: J. McGee, University of Maryland, College Park
Authors: J. McGee, University of Maryland, College Park
N. Siwak, University of Maryland, College Park
R. Ghodssi, University of Maryland, College Park
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The development and commercialization of future communication systems and biological diagnostic equipment will benefit greatly from dense integration of optical and electrical components through the use of in-plane, guided optics. Tunable optical filters are a necessary component for wavelength multiplexing and spectroscopy. However, in-plane devices have been challenging to produce as the very advantages of guided optics, small size and dense integration, lead to loss mechanisms that degrade the filter well below the performance of out-of-plane devices. Indium phosphide is our chosen material as its direct bandgap provides the possibility of integrated emitters and lasers while operating in the standard telecommunications bands of 1500-1600 nanometers at low loss. We recently demonstrated a functional in-plane tunable filter in indium phosphide and we have now improved its performance by utilizing a ribbed waveguide structure. The use of ribbed waveguides offers the advantage of a large beam less susceptible to divergence while providing single mode operation. In our device, an electrostatically-actuated doubly-clamped beam deflects a ribbed Bragg reflector relative to a stationary ribbed waveguide attached to a second Bragg reflector, forming a variable-length Fabry-Perot cavity. A simulation model we developed predicts a Q-factor of 90 compared to a Q-factor of 44 measured in the original device. The detailed fabrication, characterization, and measurement results will be presented.