Example embodiments of the present invention relate to a software programmable reconfigurable optical add drop multiplexer (ROADM) comprising of a plurality of wavelength switches and a plurality of waveguide switches, wherein when the plurality of waveguide switches are set to a first switch configuration, the software programmable ROADM provides n degrees of an n-degree optical node, and wherein when the waveguide switches are set to a second switch configuration, the software programmable ROADM provides k degrees of an m-degree optical node.

An optical switch (10) comprising: input ports (12, 14) arranged to receive optical signals from directions D1 to Dn; output ports (16, 18) arranged to output optical signals to the said directions; drop ports (20); add ports (22); a first switch array (24) arranged to receive from a first said input port (12) optical signals at a plurality of wavelengths, and comprising switch elements (26) each arranged to selectively direct optical signals to a respective drop port. The optical switch (10) further comprising optical filters (28), each arranged to receive from the first input port optical signals having bypass wavelengths, each optical filter arranged to transmit to a respective one of the output ports (18) optical signals at different bypass wavelengths; and a second switch array (30) arranged to receive from the other input ports (14) optical signals at some of said wavelengths, the second switch array comprising a plurality of switch elements (32) arranged to selectively add optical signals received from the add ports at others of said wavelengths.

In order to provide an extended branch device in which construction work is easy and communication is not significantly affected by construction work, and a method for controlling the extended branch device, the extended branch device of the present invention is provided with: a first branch unit provided with a first port coupled to a first terminal station, a second port coupled to a second terminal station, a third port, a fourth port, and a switch for coupling the first port with the second or third port and coupling the second port with the fourth port; and a first separation unit provided with a fifth port coupled to the third port, a sixth port coupled to the fourth port, and a seventh port coupled to a third terminal station, the first separation unit outputting, from the sixth port, an optical signal having a first wavelength among the optical signals inputted from the fifth port, and outputting, from the seventh port, an optical signal having a second wavelength among the optical signals inputted from the fifth port. The extended branch device is further provided with a second branch unit configured so as to be separable from the first branch unit.

A modular routing node includes a single input port and a plurality of output ports. The modular routing node is arranged to produce a plurality of different deflections and uses small adjustments to compensate for wavelength differences and alignment tolerances in an optical system. An optical device is arranged to receive a multiplex of many optical signals at different wavelengths, to separate the optical signals into at least two groups, and to process at least one of the groups adaptively.

Example embodiments of the present invention relate to a software programmable reconfigurable optical add drop multiplexer (ROADM) comprising of a plurality of wavelength switches and a plurality of waveguide switches, wherein when the plurality of waveguide switches are set to a first switch configuration, the software programmable ROADM provides n degrees of an n-degree optical node, and wherein when the waveguide switches are set to a second switch configuration, the software programmable ROADM provides k degrees of an m-degree optical node.

In order to provide an extended branch device in which construction work is easy and communication is not significantly affected by construction work, and a method for controlling the extended branch device, the extended branch device of the present invention is provided with: a first branch unit provided with a first port coupled to a first terminal station, a second port coupled to a second terminal station, a third port, a fourth port, and a switch for coupling the first port with the second or third port and coupling the second port with the fourth port; and a first separation unit provided with a fifth port coupled to the third port, a sixth port coupled to the fourth port, and a seventh port coupled to a third terminal station, the first separation unit outputting, from the sixth port, an optical signal having a first wavelength among the optical signals inputted from the fifth port, and outputting, from the seventh port, an optical signal having a second wavelength among the optical signals inputted from the fifth port. The extended branch device is further provided with a second branch unit configured so as to be separable from the first branch unit.

A method of automated testing and evaluation of a node of a communications network, the method comprising: a management computer interacting with the node to discover fibre trails within the node that can be safely tested; and the management computer interacting with the node to test at least continuity of each identified fibre trail that can be safely tested.

An optical switch suitable for use in an add/drop of an optical network node having F>1 optical fiber per direction, the F fibers together carrying optical signals comprising up to N independent wavelength channels, is disclosed. The switch includes an Optical Cross-Connect (OXC) having F input ports and N output ports. F optical splitters are connected to the OXC, the input and output ports of the optical splitters defining ports of the OXC. The OXC is controllable to switch optical signals arriving at any of the F switch input ports to the input port of any of the F optical splitters such that each switch input port is switched to an optical splitter having at least as many splitter output ports as the number of independent wavelength channels received at the switch input port. A method for splitting optical signals is also disclosed.

Telecommunications switches are presented, including expandable optical switches that allow for a switch of N inputsM outputs to be expanded arbitrarily to a new number of N inputs and/or a new number of M outputs. Switches having internal switch blocks controlling signal bypass lines are also provided, with these switches being useful for the expandable switches.

A method of automated testing and evaluation of a node of a communications network, the method comprising: a management computer interacting with the node to discover fiber trails within the node that can be safely tested; and the management computer interacting with the node to test at least continuity of each identified fiber trail that can be safely tested.