Wavelength-interleaving bidirectional circulators

We report a wavelength-interleaving bidirectional circulator, in which the even and odd ITU channels circulate in opposite handedness. Demonstrated three-port bidirectional isolation ranges from 45 dB for single-pass to 90 dB for dual-pass over the entire C-band with low loss, large flat-top bandwidth, low PDL, and good temperature stability. This new device technology is an enabler for bidirectional optical networks and opens up a range of possibilities for bidirectional fiber devices: isolators, circulators, add-drops, cross-connects, and uni- to bidirectional optical network interfaces.