A bidirectional optical add-drop multiplexer with gain using multiport circulators, fiber Bragg gratings, and a single unidirectional optical amplifier

We propose and demonstrate a new bidirectional optical add-drop multiplexer (BOADM) with gain based on multiport optical circulators and fiber Bragg gratings. The BOADM incorporates a single unidirectional optical amplifier and can flexibly accommodate asymmetric traffic. The device achieves more than 13 dB of bidirectional gain and has low inband crosstalk (below -45 dB) and low out-of-band crosstalk (below -30 dB). Moreover, the device removes Rayleigh backscattered light and out-of-band amplified spontaneous emission noise. The power penalty is negligible for all through and add-drop channels in both directions when the BOADM is used in a 6 *10 Gb/s bidirectional wavelength-division-multiplexing transmission system over 80 km of standard single-mode fiber.