US 9,813,182 B2
Submarine reconfigurable optical add/drop multiplexer with passive branching unit
Philip N. Ji, Princeton, NJ (US); Ryuji Aida, Tokyo (JP); and Ting Wang, West Windsor, NJ (US)
Assigned to NEC Corporation, Tokyo (JP)
Filed by NEC Laboratories America, Inc., Princeton, NJ (US)
Filed on Aug. 7, 2014, as Appl. No. 14/454,031.
Claims priority of provisional application 61/863,005, filed on Aug. 7, 2013.
Prior Publication US 2015/0043920 A1, Feb. 12, 2015
Int. Cl. H04J 14/02 (2006.01)
CPC H04J 14/021 (2013.01) [H04J 14/0205 (2013.01); H04J 14/0208 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for data transport using one or more submarine reconfigurable optical add/drop multiplexing systems, comprising:
wherein the optical spectrum is separated into a wavelength division multiplexed (WDM) signal spectrum for WDM signals, and a loading light spectrum, and wherein the WDM signal spectrum is alternating odd and even channels;
tuning a laser wavelength at the transmitter at a trunk terminal between odd wavelengths and even wavelengths according to a respective target destination;
within a branching unit, passively directing with three interleavers, one for each trunk terminal, and three de-interleavers, one for each trunk terminal, each channel to the respective target destination;
interconnecting the three interleavers and the three de-interleavers in a configuration that the two output ports of the interleaver for each trunk terminal are respectively connected to an input port of the de-interleavers for the other two trunk terminals;
using optical band pass filters to separate and combine signals at the WDM signal spectrum and the signals at the loading light spectrum;
setting loading light at each trunk terminal to maintain power balance for all paths from a source terminal to the branching unit;
recycling the loading light at the branching unit for the path from the branching unit to a destination terminal; and
at the destination terminal, receiving signals from one or more terminals combined by the de-interleavers at the branching unit.