We present the design guidelines for novel passive ar-\ud
rayed waveguide grating (AWG) devices to all-optically implement\ud
time-frequency packing techniques in orthogonal frequency divi-\ud
sion multiplexing (OFDM) systems. The proposed approach can\ud
increase the spectral efficiency in long-haul fiber links. We analyze\ud
the system performances, evaluating the maximum achievable in-\ud
formation rate and spectral efficiency, and we found the optimal\ud
AWG layout to maximize the overall system capacity. We demon-\ud
strate, through simulations, that an overall 1.4 Tb/s transmission\ud
over 200 GHz bandwidth can be reached, using two polarizations,\ud
quadrature phase shift keying modulation, and digital feedback\ud
equalization