Simulation Study in Design of Miniaturized MID-Infrared Sensors

B. Mizaikoff, X. Wang, and S.-S. Kim
Institut für Analytische und Bioanalytische Chemie
Universität Ulm
Ulm, Deutschland

Evanescent-wave optical waveguide is widely used as sensing platform for chemical/biological sensor applications. Our research group contributed to on-chip IR sensor technology and made recent progress in miniaturizing such devices utilizing quantum cascade lasers (QCL) in combination with planar GaAs/Al0.2Ga0.8As waveguides. Furthermore progress is reported toward microfabricated Mid-infrared (MIR) GaAs/Al0.2Ga0.8As waveguide based on strip waveguide and microring resonators.

Comsol Multiphysics provides a simple framework for design and optimization of waveguide structures. Finite element modeling (FEM) was applied for advanced mode analysis and for studying the beam propagation properties in various structured waveguides. The enhancement factor of evanescent field is calculated to be 1-2 order of magnitude compared to non-structured strip waveguide.