Using the Optical Backscatter Reflectometer (OBR) with Multi-Mode Fibre

This engineering note details two methods of coupling light from single mode fiber to multi-mode fiber to produce stable and repeatable Insertion Loss (IL) and Return Loss (RL) measurements with LUNA’s Optical Backscatter Reflectometer (OBR). This note also discusses the differences between IL and RL results for the two mode launch conditions and details the consequences for OBR spatial resolution so that the user may choose the launch method which best suits their application.