The OSA205 from Thorlabs Inc is a Optical Spectrum Analyzer with Wavelength Range 1.0 to 5.6 µm, Wavelength Resolution Spectral Resolution: 7.5 GHz (0.25 cm-1), Wavelength Accuracy Spectral Accuracy: ±2 ppmf, Dynamic Range Optical Rejection Ratio: 30 dB, Optical Power Range 10 mW (10 dBm). More details for OSA205 can be seen below.