Mohammadreza Fasihanifard, Muthukumaran Packirisamy
Journal of Optical Microsystems, Vol. 5, Issue 01, 014001, (December 2024) https://doi.org/10.1117/1.JOM.5.1.014001
TOPICS: Design, Actuators, Electrodes, Optical microsystems, Microelectromechanical systems, Optical actuators, Waveguides, Fabrication, Silicon, Photonic integrated circuits
Selecting micro-electromechanical actuators with high force output, broad traveling ranges, and robust reliability becomes increasingly critical for active optical microsystem devices. We offer a comparative analysis of electrostatic comb actuators tailored for optical applications, focusing on evaluating performance for the demands of force density, traveling range, and footprint. Previous analyses often examined force generation in isolation, without a comprehensive assessment of these actuators’ footprint efficiency and practical traveling range. By integrating these parameters, we provide new insights into the suitability of various electrode designs for optical microsystems, thus offering a broader perspective on actuator selection. Our analysis particularly emphasizes silicon platforms with a dedicated microelectromechanical system layer, where optical waveguides are fabricated on top, resulting in enhanced mechanical stability and reliability. We delve into the implications of different configurations, considering the delicate balance between maximizing force, minimizing footprint, and maintaining operational travel range. Our findings reveal that actuators combining gap-closing and area-overlap mechanisms achieve superior performance by covering a larger range of force densities and traveling ranges with lower actuation voltages. This design excels in both small and large traveling ranges and is a strong candidate for photonic applications requiring high force and large traveling ranges within a compact footprint. In addition, we present a comprehensive map of the operational regimes for each actuator type, enabling a targeted selection based on the specific requirements of photonic applications. We aim to assist in microelectromechanical actuator designs for optical microsystems, empowering designers to make informed decisions for electrode configurations that meet the nuanced demands of specific optical microsystem applications.