These singlemode tap couplers tap or split off power levers from 0.5% to 5% from transmitted light signals over broad wavelength windows at either 1310- or 1550-nm operating wavelengths. Customer-specified tap coupling ratios such as 1% can be accommodated. According to the manufacturer, the devices exhibit excellent thermal and polarization stability as well as low excess-loss performance. They can be used in any application that requires signal monitoring or feedback control loops such as optical amplifiers and receivers, telecommunications and cable-TV networks, and test and measurement instrumentation. The couplers are available in 1ٴ or 2ٴ port configurations, and package options include miniature, ruggedized, or modular cartridges.