Wavelength-selective cross connect featuring wide flat passband and high cascadability for WDM optical networks

A new reconfigurable wavelength-selective optical cross connect (OXC) featuring wide flat passband and high cascadability is proposed. It is demonstrated by 10-Gb/s /spl times/ 8-channel wavelength-division-multiplexing (WDM) transmission (0.8-nm channel spacing) over 4000 km. In the transmission line end with a single OXC, the electrical signal-to-noise ratio (SNR) degradation caused by inserting the proposed OXC is negligible, unlike the 1-dB SNR degradation with a conventional OXC. In the transmission line with an eight-unit OXC cascade, the bandwidths yielding 3-dB SNR degradation for the proposed OXCs, and the conventional OXCs, are 0.6 and 0.1 nm, respectively. The cascade of the proposed OXCs has such a wide passband, that there is nearly no narrowing compared to the 0.8-nm channel spacing.