The Agilent 81640A tunable laser source covers both C- and L - Band. It is specially designed for testing critical DWDM passive components. The 81640A works in both DWDM bands (C- and L-band). It has continuous sweep through full wavelength range, 4 complete spectral bands (E-, S-, C-, and L- band) coverage with 2 lasers, fast tuning speed with dynamic specification, low source spontaneous emission output for high dynamic range, high power optical output for optical amplifier, built in real-time wavelength meter, mode-hop free tuning over full wavelength range and Panda type polarization maintaining fiber outputs.