AR-Coated PM Patch Cable

Fibermart AR coating PM Patch Cable is designed to minimize reflections when either launching a free-space beam out of a fiber or coupling a free-space beam into a fiber. The coated connector provides an average reflectivity of <0.5% over the designated AR coating range without affecting the extinction ratio of the fiber (see the AR Coating tab for plots of reflectivity vs. wavelength).

Fiber-to-Free Space Coupling, When coupling light from an uncoated fiber into free space, such as when using fiber collimators, the return loss (signals reflected back to the source instead of exiting the fiber) at the glass-air interface at the fiber end will be worse than experienced during fiber-to-fiber coupling. This is due to Fresnel reflections at the interface, which are typically ~4%.