Low loss polycrystalline SiGe core fibers for nonlinear photonics

Polycrystalline silicon-germanium (SiGe) core fibers offer great potential as flexible platforms for microscale optoelectronic and nonlinear optical devices. Compared to silicon (Si) core fibers, the SiGe material provides the potential for higher nonlinear coefficients, extended mid-infrared wavelength coverage, and a means to tune the bandgap and index of refraction by varying the Ge composition. Here, SiGe core fibers (10 at% Ge) were fabricated using the molten core drawing method, followed by CO