Optical and structural numerical simulation of SU-8: Optical accelerometer

Andreu Llobera, V. J. Cadarso, V. Seidemann, S. Büttgenbach, J. A. Plaza

Research output: Contribution to journalArticleResearchpeer-review

Abstract

This contribution deals with the numerical simulation of SU-8 devices. We introduced a new integrated polymer optical accelerometer based on intensity modulation formed by a SU-8 polymer structure. The SU-8 polymer is used as structural material but also as optical waveguide. It consists of one mass adjoined to four mechanical beams, all of them made of SU-8. There are three aligned optical waveguides: one on the inertial mass and two additional fixed to the substrate. Any applied acceleration will misalign the three waveguides; the losses show the acceleration level. The paper is focused on the numerical simulation of this device. It is a one-way sequentially coupled analysis. Firstly, a Finite Element Method (FEM) simulation is done to calculate the mechanical sensitivity of the structure. In parallel, the beam profile at the waveguides is computed by using the Non-Uniform Finite Difference Method (NU-FDM). Finally, the evolution of the light beam in the propagating axis of the waveguides is simulated using the Beam Propagation Method (BPM) by introducing the results of the previous simulations as loads. The good agreement between the experimental results and the simulation demonstrates the feasibility of the sequential couple of the mechanical and optical fields by using the three different numerical methods. Mechanical sensitivity, frequencies of the vibration modes and optical ligth transmission are demostrated to be calculated by numerical simulation. This possibility oppens the optimization of mechanical SU-8 sensors for any application.

Original languageEnglish
Pages (from-to)106-114
Number of pages9
JournalSensor Letters
Volume6
Issue number1
DOIs
Publication statusPublished - 1 Feb 2008

Keywords

  • Micro-opto-electromechanical systems (MOEMS)
  • Optical accelerometers
  • Polymer technology
  • SU-8

Cite this