US 11,675,133 B2
Optical add/drop device and assembly, and communications network node
Sergio Mosti, Genoa (IT); Sergio Lanzone, Genoa (IT); Marco Assale, Genoa (IT); Claudio D'Incà, Genoa (IT); and Alberto Deho, Genoa (IT)
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), Stockholm (SE)
Appl. No. 17/289,984
Filed by Telefonaktiebolaget LM Ericsson (PUBL), Stockholm (SE)
PCT Filed Oct. 30, 2018, PCT No. PCT/EP2018/079730
§ 371(c)(1), (2) Date Apr. 29, 2021,
PCT Pub. No. WO2020/088746, PCT Pub. Date May 7, 2020.
Prior Publication US 2021/0396933 A1, Dec. 23, 2021
Int. Cl. H04B 10/00 (2013.01); G02B 6/293 (2006.01); H04B 10/25 (2013.01); G02B 6/42 (2006.01)
CPC G02B 6/29365 (2013.01) [G02B 6/29383 (2013.01); G02B 6/4246 (2013.01); H04B 10/2589 (2020.05)] 13 Claims
OG exemplary drawing
 
1. An optical add/drop device comprising:
a common port;
an add port;
a first wavelength selective optical filter configured to:
receive an optical signal at an add wavelength from the add port and transmit said optical signal at the add wavelength towards the common port; and
receive optical signals from the common port and reflect optical signals not at the add wavelength;
a second wavelength selective optical filter configured to receive said optical signals from the common port reflected by the first wavelength selective optical filter and transmit an optical signal at a drop wavelength, different to the add wavelength, the optical signal being from among said optical signals received from the common port and reflected by the first wavelength selective optical filter;
a drop port;
an optical waveguide configured to receive said optical signal at the drop wavelength transmitted by the second wavelength selective optical filter and route said optical signal to the drop port; and
an express port,
wherein the second wavelength selective filter is additionally configured to:
receive said optical signals from the common port reflected by the first wavelength selective optical filter and reflect optical signals not at the drop wavelength towards the express port;
receive optical signals from the express port and reflect optical signals not at the drop wavelength;
wherein the first wavelength selective filter is additionally configured to receive said optical signals from the express port reflected by the second wavelength selective filter and reflect said optical signals towards the common port.