Wide dynamic range for 50 GHz WDM-Signals: The dynamic range is 70 dB at peak ±0.4 nm, and 60 dB at peak ±0.2 nm. High-resolution measurement achieves wide dynamic range with 50 GHz spacing WDM system. High wavelength accuracy: Provides ±0.02 nm wavelength accuracy at 1520 to 1580 nm, and ±0.04 nm at 1580 to 1620 nm, with ±0.01 nm wavelength linearity, making it especially useful for high-precision loss wavelength characteristics and other evaluation of WDM devices.