Diamond Encapsulated Silicon Optical Fibers

The growth of single-crystal diamond by chemical vapor deposition (CVD) has been a long-standing research direction within the CDAC scientific program. These studies have included the development of CVD chamber technologies as well as the optimization of diamond growth chemistry and the analysis of the enhanced strength and toughness of CVD diamond as compared the natural material. In a recent outgrowth of these studies, a collaboration between Penn State University and CDAC has resulted in the first silicon optical fibers encapsulated by diamond grown by CVD methods (Fig. 1). These fibers, which have a homogeneous diamond morphology over their entire length, have been shown to guide infrared light, and may provide significant enhancements in remote sensing and structural monitoring in extreme environments or when probing for chemical signatures at mid-infrared wavelengths.

Hendrickson, A.T. et al., Diamond Encapsulated Silicon Optical Fibers Synthesized by Chemical Vapor Deposition. AIP Advances 10, 095009 (2020).

SEM images of a diamond fiber at different magnifications showing the homogeneous morphology of crystalline diamond faceting encapsulating a silicon optical fiber.