What else can an AWG do?

The present paper aims to describe other functionalities for an arrayed waveguide grating (AWG)-based device, showing that this widely used configuration can be designed not only to frequency multiplex/demultiplex wavelength division multiplexing (WDM) signals, but also to perform the discrete Fourier transform (DFT) and the discrete fractional Fourier transform (DFrFT) of a signal, in all-optical orthogonal frequency division multiplexing (OFDM) systems. In addition 1 × N and N × N phased array switches architectures are described, as well as a new configuration to perform polarization diversity demultiplexing. Finally, a general approach, based on an analogy with the finite impulse response (FIR) filter approach, is presented to design optical modulators for any modulation format, using either phase modulators (PM) or electro-absorption modulators (EAM).