Time-space-conversion optical signal processing using arrayed-waveguide grating

Ultrafast optical signal processing over 100 Gbit/s data rate, which is difficult to do by traditional electronic means, has been achieved using time-space-conversion technology. Such processing enables many operations such as the formation, reshaping, pattern recognition and even routing of an ultrafast bit stream. This technology has been widely demonstrated by using free-space optics with diffraction grating pairs and lenses at visible wavelengths. We have proposed time-space-conversion optical signal processing using an arrayed-waveguide grating. We show the schematics of time-space-conversion processing systems using (a) diffraction gratings and (b) arrayed-waveguide gratings. In both systems, a temporal waveform is converted to a frequency spectrum in the focal plane by the dispersive element. The frequency spectrum is then modulated in parallel by a spatial filter and reconverted to a reshaped temporal waveform.