Keysight-Agilent 8156A
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.