Inverse Fourier transform method for characterizing arrayed-waveguide gratings

A new characterization method of phase and amplitude errors in arrayed-waveguide gratings (AWGs) based on inverse Fourier transformation (IFT) is presented. It overcomes the limitations of previous optical low-coherence methods (OLCs), allowing the characterization of AWGs with any step increment ((delta)L). The method has been successfully used to characterize an AWG with a (delta)L of only 23 (mu)m. A comparison between the results from IFT and OLC methods shows a standard deviation of the phase errors of 2(degree) for an AWG with a (delta)L of 51 (mu)m.