Optical switch, optical switch apparatus and node, and communication network
F Testa, A Bianchi, F Cavaliere - US Patent 9,746,747, 2017 - Google Patents
An optical switch has four optical ports; a first optical waveguide coupled between a first of
said ports and a second of the ports; a first switch element provided between the first …
said ports and a second of the ports; a first switch element provided between the first …