Patent ID: 10416401

Abstract:
In-line uni-directional optical tap detector devices provide optical power monitoring in a small, inexpensive form factor. A pair of optical fibers with angled end surfaces are fusion-spliced or butt-coupled together, with a thin-film coating or coating stack positioned in between the two fiber end surfaces. The thin-film coating or coating stack acts as an optical tap, reflecting a small portion of the optical signal towards a photo-detector affixed to the exterior of the cladding of the fibers, positioned and angled such that the photo-detector measures the optical power of signals propagating in one direction down the fibers, while ignoring signals propagating in the opposite, or reverse direction. Alternately, a V-groove block or fiber holder is used to position and secure the fibers, without requiring fusion splicing, where the reflection of a portion of the optical signal to the photo-detector may be due to Fresnel reflection at the fiber end surfaces.