Pure Silicon Photonic Crystal Fiber Fabrication via Magnesiothermic Reduction for Operations in the Mid-IR Spectrum

Abstract

Researchers at the University of Central Florida have developed a novel process for directly converting silica photonic crystal fiber (PCF) into pure silicon PCF. In photonic crystal devices, there exists an ability to confine light to a very small cross-section. This results in a new style of guiding which has lead researchers around the world to envision novel applications that exploit this highly confined and guided light.

One such application, the photonic crystal fiber (PCF), is a threaded version of the photonic crystal and is applicable in communications, lasers, nonlinear conversion, and more. Research into silica (SiO2) PCF devices has been intensive and productive; proving itself a valuable technology. Unfortunately, the transition to pure silicon (Si) devices, featuring low loss in the mid-IR, high optical damage threshold, and wide availability, is not yet commercially feasible.

Technical Details

The UCF technology defines a process that uses magnesiothermic reduction. During the process, a magnesium gas pulls the oxygen away from the silica device. This is the very first method which has shown the ability to fabricate pure silicon PCF.

The fabrication method preserves the nanostructure of the silica in the raw material during the conversion to silicon. In some embodiments, the hollow-core silica fiber used as a raw material has a honeycomb-shaped photonic crystal structure around a hollow core. The use of silicon in the converted fiber provides low absorption loss in the mid-IR range, an extremely high optical damage threshold, and excellent thermal conductivity. The use of nanostructured silicon (ns-Si) extends the low absorption loss into near-IR and improves third-order non-linearity (because of quantum confinement).

Benefit

Market Application