The AP2050A from Apex Technologies is a Optical Spectrum Analyzer with Wavelength Range 1526 to 1567 nm, Wavelength Resolution 0.16 to 16 pm@140 MHz to 2 GHz, Wavelength Accuracy ±3 pm, Dynamic Range 83 dB, Sweep Time Between 0.4 nm/s (min) & 1.2 nm/s (max). More details for AP2050A can be seen below.