Trigonometric Transforms for High-Speed Optical Networks: All-Optical Architectures and Optical OFDM

In this paper, it is shown that the use of real trigonometric transforms can advantageously replace the Fourier transform in optical communication systems, for both all-optical and electronic signal processing. All-optical discrete Hartley transform (DHT) and discrete Cosine transform (DCT) architectures for high-speed optical signal processing, filtering and data compression are given and compared to fiber Fourier processing. A trigonometric transform-based orthogonal frequency division multiplexing (OFDM) transmission system is also presented. The modulation/demodulation is performed by using the fast Hartley transform (FHT) algorithm. The simplified scheme and the real processing make it suitable for direct detection optical systems.