Highly Sensitive Micro-Opto-Electromechanical Systems Accelerometer Based on MIM Waveguide Wavelength Modulation

Abstract

In this article, a novel micro-opto-electro- mechanical system (MOEMS) accelerometer sensor based on metal–insulator–metal (MIM) waveguide wavelength modulation is proposed. The device senses the vibration signal of external acceleration by the mechanical sensing system and uses the MIM waveguide in the optical sensing system to sense the displacement of the mechanical vibration component to cause the change of the light wavelength. The characteristics of the optical sensing system and the mechanical sensing system of the MOEMS accelerometer are analyzed by the finite-difference time-domain (FDTD) and finite-element analysis (FEA) methods, respectively. The simulation results show that the proposed accelerometer sensor has an optical system sensitivity of up to 7.827 in the wavelength modulation range of 1– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$12~\mu \text{m}$ </tex-math></inline-formula> , a mechanical sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.292963~\mu \text{m}$ </tex-math></inline-formula> /g, a natural frequency of 939.28 Hz, and a linear measurement range of ±4.4 g. Surprisingly, we obtained accelerometer sensitivity up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.293~\mu \text{m}$ </tex-math></inline-formula> /g and resolution up to 436.1 ng ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\delta \lambda ={1}$ </tex-math></inline-formula> pm). We also show the performance advantages of this accelerometer with high sensitivity and high resolution over the measurement range by comparing this MOEMS accelerometer sensor with previously reported work. Based on these performance characteristics, we expect this work to be widely used in high-precision measurements for inertial navigation.