The 1601-PXI from Quantifi Photonics is a Optical Power Meter with Measurement Range(Power) -50 to 20 dBm, Wavelength Range 1260 to 1650 nm, Linearity ±0.1 dB @ - 40 dBm to 0 dBm, ±0.15 dB @ -50 dBm to - 40 dBm. More details for 1601-PXI can be seen below.