Optimizing fiber coupling with a quasi-passive microoptical bench

• Published in: Journal of microelectromechanical systems Vol. 14; no. 6; pp. 1339 - 1346
• Main Authors: Biao Li, Wirz, H., Sharon, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Alignment; Benches; Devices; Exact sciences and technology; Fiber coupling; Fibers; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Joining; laser trimming; Mechanical instruments, equipment and techniques; Micromechanical devices and systems; microoptical bench; nanoscale motion; Optical coupling; Optical fiber devices; Optical fibers; Optical films; Optical filters; Optical materials; Optical receivers; Optimization; Packaging; Photonics; Physics; Platforms; residual stress; Semiconductor materials; Silicon; stoichiometric silicon nitride film; Integrated optics; stoichiometric silicon nitride film; Actuators; laser trimming; Submicrometer; Optical bench; Manipulators; Residual stresses; High-resolution methods; Micro-optics; Optimization; Deposition process; nanoscale motion; Thin films; microoptical bench; residual stress; Alignment; Tensile stress; Silicon nitrides; Fiber coupling; Microelectromechanical device; Biased estimation
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2005.859091

While the silicon microoptical bench with purely passive locational features was an attempt at breadboard-like integration for photonic applications, it failed to provide the high-precision alignment required for efficient light coupling between devices and/or fibers. To optimize the final alignment without the introduction of on-board active actuators or external high-precision manipulators, we have developed and demonstrated a low-cost, micromachined optical bench with quasipassive locational features capable of submicron alignment optimization. The concept capitalizes on inherent residual tensile stresses produced during the stoichiometric Si/sub 3/N/sub 4/ thin-film deposition process. By selectively trimming stress element on either side of a suspended platform, the equilibrium position can be biased to one side or another, enabling high-resolution relative motion between the suspended platform and the base. We have demonstrated, as a first attempt, high-efficiency fiber-to-fiber alignment using this concept. [1556].