Targeted at providing advanced test solutions, the OSA-160, OSA-161, and OSA-201, JDSUs field-ready full-band DWDM analyser modules, use a new grating-based monochromator design (JDSU patents). These analysers offer high optical selectivity and high measurement speed for accurate measurement of wavelength, power, and optical signal-to-noise ratio (OSNR) in the presence of multiple channels.