Reconfigurable optical filter based on digital mirror arrays

We present a reconfigurable optical filter with multiple passband channels based on the combination of a diffraction grating and an array of digital micromirrors. The filter allows for adjustment of the central frequency of its individual passband channels to match standard wavelength grids with precision better than 0.033 nm. The number of channels, the channel passband width, and the channel peak profile can be dynamically reconfigured by changing the periodic pattern imposed to the digital micromirror array. Experimental results are in excellent agreement with basic design relations describing the spectral characteristics of the filter.