This tab provides a brief explanation of how we determine several key specifications for our 1x2 couplers. 1x2 couplers are manufactured using the same process as our 2x2 fiber optic couplers, except the second input port is internally terminated using a proprietary method. Thorlabs' Single Mode 1x2 Fiber Optic Couplers, also known as taps, have a flat spectral response across the entire specified range. They are available with a coupling ratio of 50:50, 75:25, 90:10, 99:1, or 99. Our Multimode Fiber Optic Couplers come standard with 62. 1x2 Single Mode (SM) Fiber Splitters/Couplers allow for a single fiber input to be split into two outputs or for multiple inputs to be combined into one output.