Demonstration of N/2 2 × 2 Optical Cross-Connectors in One Pair of N × N Cyclic-AWGs and Multiple Tunable Fiber Gratings

A routing device with N /2 2 × 2 optical cross-connectors (OXCs) is based on a pair of N x N cyclic array waveguide gratings (AWGs) and multiple tunable fiber Bragg gratings (FBGs) to realize the dense wavelength-division multiplex (DWDM) channel configuration. A free spectral range (FSR) in the N × N cyclic AWG is N channel spacing between two adjacent DWDM channels for each port pair. Planning every two-port pairs of the AWG is to effectively allocate the FSR for allowing the input of N /2 separates the groups of DWDM channels. In this way, the DWDM channels in N /2 groups can be demultiplexed into output ports of the AWG with intervals of two channel spacings. A multiple tunable FBGs can be used to reflect the DWDM channels into one output port of the 2 × 2 OXC or be tuned into the interval of the FSR to make the DWDM channels pass through directly into the other output port. As a result, the proposed routing device costs little and offers more flexible scalability in a dynamic DWDM network.