Hollow-Core-Integrated Optical Waveguides for Mid-IR Sensors

Integrated hollow-core antiresonant reflecting optical waveguides are designed and analyzed for mid-infrared propagation. With a proper selection of waveguide materials and geometry, low loss propagation lower than 1.5 dB/cm in the whole 2.5-14 mu m range could be achieved. Single-mode waveguides, with a modal purity above 95% after propagation lengths of few millimeters, have been designed at 4 and 9 mu m. The waveguides could be realized using fabrication andmaterials fully compatiblewith standard Silicon technology, enabling the chip-scale integration of Mid-IR devices for gas sensing applications.