OPTICAL MATERIALS: Semiconductor-core fiber promises novel nonlinear fiber-based devices

摘要

Optical fiber with a semiconductor core has the potential to unify long, flexible, and robust fiber-based waveguides with the nonlinear, Raman, and infrared transparency of semiconductor planar waveguides. Crystalline semiconductor core optical fibers are still in their infancy but are generating growing interest globally. Such fibers--which are currently focused on Group IV and III-V semiconductors--have the potential to marry the benefits of long, flexible, and robust fiber-based waveguides with the nonlinear, Raman, and infrared (IR) transparency of semiconductor planar waveguides. Our initial successes in glass-clad semiconductor optical fibers fabricated using a molten core method include cores of crystalline silicon, germanium, and indium antimonide (see Fig. 1). In the molten core method, the semiconductor is placed inside a cladding glass tube. The cladding glass is chosen such that the semiconductor core is molten at the temperature where the glass cladding is drawn into fiber. In essence the cladding glass serves as a crucible to confine the semiconductor melt as the glass crucible draws directly into optical fiber.