The HP 8156A is a high performance optical attenuator (1200
to 1650 nm) for single-mode and multimode applications. The HP 8156A is available with Option 201 to select
the desired return loss performance of 60 dB. Using the built-in back reflector mode and an external reference
reflector (81000BR), the 8156A can be used as a programmable back reflector to measure component and system
sensitivity against reflections.
The attenuation range is 60 dB with 0.001 dB resolution between 1200
nm and 1650 nm. Due to a novel single filter design, no ranging occurs. This completely eliminates dark spots
or potential attenuation overshoots or undershoots. Attenuation accuracy is typically better than ±0.05 dB with
a polarization sensitivity of less than 0.02 dB peak-to-peak.