An optical system comprising a combination optical switch and monitoring system based on an array of mirrors, and a moveable reflective element co-packaged together, including discrete sets of fiber ports wherein λn from input fiber ports is focused on λn mirror via the use of shared free space optics; such as shared beam steering elements, dispersive elements, and optical elements, and discrete arrays of MEMS mirrors utilized to select and switch selected wavelengths from the input fiber port(s) to an output fiber port(s) of the optical switch, and wherein a moveable reflective element sharing the same free space optics is utilized to sweep across and reflect selected portions of the optical spectrum back to a photodetector. By correlating reflective element position with power measured, a processor can obtain a spectral plot of the wavelength band of interest, as well as calculate parameters such as center wavelength, passband shape, and OSNR.