Laser Source 1310nm, 13dBm. The Agilent (now Keysight) 8165xA Fabry-Perot laser sources are single- or dual-wavelength modules to be used in conjunction with optical power meter modules for insertion loss, optical return loss and PDL measurement of broadband components and fiber. The 8165xA Fabry-Perot lasers are insensitive to back reflections and are stabilized for short and long-term applications. For convenience there are single and dual wavelength source modules, available with an output power of up to +13 dBm. The output power of the sources can be attenuated for applications where lower power is needed.