Agilent's 81613A Return Loss module is the tool of choice for measuring return loss (RL) and reflection of single-mode fiberoptic components. The module measures the optical power into and reflected back from the device under test and calculates and displays the return loss. Thorough built-in functionality provides the correct coupling and detection ratios and eliminates the effects of dark current and residual backscatter in the instrument setup to provide accurate measurements over a wide dynamic range. The Return Loss modules can be used in any 816x Lightwave mainframe and with the internal Fabry-Perot light source or an external fixed-wavelength or tunable laser source. The performance and usability is enhanced by combination with an Agilent power sensor in the 8163B mainframe for simultaneous RL and insertion loss measurements, especially in combination with the 81610CC calibrated reference cable. Automated use is supported by the 816x Plug&Play Driver, which also supports use of the module for advanced swept-wavelength RL measurements Features Return loss dynamic range > 75dB Wide operating wavelength range: 1250nm to 1640nm Built-in Power Monitor and Laser Source Built-in step-by step guided wizard with 8163B mainframe