A 2 × 2 Optofluidic Multimode Interference Coupler

The feasibility of an optofluidic $hbox{2}timeshbox{2}$ multimode interference (MMI) coupler based on a liquid-core antiresonant reflecting optical waveguide (ARROW) is proposed. The device exhibits interesting spectral properties related to the ARROW structure and the multimodal interference effects that can be easily tuned by simply changing the liquid core. The device has been fabricated using standard silicon technology. The experimental results are in good agreement with simulated ones, and confirm the possibility of realizing a reconfigurable MMI coupler.