All-optical multi-wavelength header recognition using superimposed Bragg gratings based correlators

We have demonstrated that an optical correlator, based on superimposed Bragg gratings, can be used as all-optical multi-wavelength header recognition in optical packet switching networks. The proposed correlator is composed of two superimposed gratings in conjunction with variable delay lines. These superimposed Bragg gratings are used to demultiplex and multiplex the wavelength components of multi-wavelength header bit patterns. The variable delay lines create a wavelength profile that can be matched with any arbitrary bit patterns. Simulation results for all optical recognition of four-bit patterns at 10?Gbps are reported. The results show that when the header bit pattern matches the wavelength profile of the correlator, the generated auto-correlation function will include a high amplitude peak; otherwise, a cross-correlation function with low amplitude peaks will be generated in the output of the correlator. Considering this idea, multi-wavelength header is recognized by using all-optical processing method. Copyright (C) 2012 John Wiley & Sons, Ltd.