Return Loss Module 1250nm-1640nm, High Return Loss Dynamic Range: > 70dB Agilent (now Keysight) 81610A is a Return Loss Module for measuring return loss (RL) and reflection of single-mode fiberoptic components. The Return Loss modules can be used in any 816x Lightwave mainframe and an external fixed-wavelength or tunable laser source. The performance and usability is enhanced by combination with a Keysight 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. Return loss dynamic range: > 70 dB Return loss uncertainty: down to ±0.25 dB with broadband source Wavelength range: 1250 nm to 1640 nm Built-in power monitor Built-in step-by step guided wizard with 8163B mainframe