An Optical Time Domain Reflectometer (OTDR) is commonly used for measurement of fusion splice loss. The basic backscattering principle makes the OTDR very sensitive to fibre MFD dependent light coupling properties. This application note discusses the splice loss measurement technique and investigates the extrinsic and intrinsic factors a ecting the splice loss measurements when joining two bare fibre strands. Splice loss refers to the part of the optical power that is not transmitted through the splice and is. Splicing is required to create a continuous path for light transmission from one fiber to another. 05 dB per splice for standard SMF-SMF. Later, comparisons can be made.