Wavelength selective switches for SDM networks

Space division multiplexing (SDM) technology is becoming more attractive because it offers large transmission capacity of a multiple of the spatial channel count. For applications to core and metro networks, switching devices are needed that can handle both wavelength and space channels. An SDM network with "uncoupled" SDM media such as multi-core fiber (MCF) provides a degree of freedom of spatial switching in addition to wavelength switching. Here we demonstrate wavelength selective devices for an MCF-based SDM network. A wavelength selective switch with core-by-core switching, a wavelength cross-connect for SDM channel interexchange, and a gain equalizer for a multi-core erbium doped fiber amplifier are demonstrated by using the spatial and planar optical circuit platform, which utilizes the advantages of free-space and waveguide optics.