Optical FFT/IFFT circuit realization using arrayed waveguide gratings and the applications in all-optical OFDM system

Area of Science:

• Photonics and Optical Engineering
• Signal Processing

Background:

• Arrayed waveguide gratings (AWGs) are established components for wavelength division multiplexing (WDM) in optical networks.
• Existing AWG designs are optimized for multiplexing and demultiplexing functionalities.

Purpose of the Study:

• To propose and demonstrate the novel application of conventional AWGs as integrated spectral filters for optical Fast Fourier Transform (FFT) and inverse FFT (IFFT) operations.
• To explore the potential of AWGs in advancing optical signal processing, particularly for optical Orthogonal Frequency Division Multiplexing (OFDM) systems.

Main Methods:

• Leveraging the inherent wavelength selection properties of AWGs to perform FFT/IFFT functions.
• Developing and simulating an all-optical OFDM system architecture utilizing AWGs for spectral filtering.

Main Results:

• Demonstrated that the operational principles of AWGs for MUX/DEMUX directly enable FFT/IFFT capabilities.
• Showcased reduced structural complexity for AWG-based optical FFT/IFFT circuits compared to alternative methods, especially for high-port-count devices.
• Presented simulation results validating the feasibility of an all-optical OFDM system employing AWGs.

Conclusions:

• AWGs offer a viable and structurally simpler approach for implementing optical FFT/IFFT functions.
• AWGs present a promising solution for all-optical OFDM systems, particularly those requiring a large number of optical subcarriers.