Integrated‐optic OFDM signal multiplexer composed of optical IFFT circuit.

An integrated optical device that is able to multiplex modulated signals to an optical orthogonal frequency division multiplexing (OFDM) signal directly in the optical domain is demonstrated. The device operates based on optical inverse fast Fourier transform (IFFT). It is composed of directional couplers, delay lines and a combiner, which was fabricated with silica waveguide technology. The operation was experimentally confirmed by generating 40 and 80 Gbit/s optical OFDM signals. [ABSTRACT FROM AUTHOR]