Compact Optical MEMS 1xN Beam-Splitter Based on Multi-Mode Interference for Optofluidic Applications

Abstract

In this work, we present the design and characterization of a 1xN beam splitter based on an MMI waveguide fabricated on MEMS technology. The proposed structure also has the advantage of allowing the splitter to be used at wavelengths below the 1.1 µm silicon cut off wavelength that is needed for many optofluidic applications. A compact splitter design is achieved by guiding the light in air in a parallel plate waveguide structure with the lowest achievable guiding refractive index, with paired excitation in the input and parabolic tapering in the waveguide width along its length. The structure is simulated at different wavelengths using a wide angle FD-BPM technique. Measurement results of the fabricated structure are also shown at wavelengths of 1310 nm and 980 nm.