Optical amplifier arrangement

An optical amplifier arrangement comprising;

• an amplifier section, comprising:
• a splitter for providing an input WDM optical signal on at least first and second output paths;
• and
• an optical amplifier for amplifying the WDM optical signal in at least one of the paths;
• and
• a switching core section at the output of the amplifier section, comprising:
• a de-multiplexer for dividing an amplified WDM signal into individual channels or groups of channels;
• a splitter for providing the divided channels on at least third and fourth output paths;
• an optical switching core in each of the third and fourth paths;
• and
• a switch for selecting the output of one of the switching cores.

A method of upgrading an optical amplifier arrangement, comprising:

• defining a first path between an input and an output of the amplifier arrangement, the first path including a splitter;
• amplifying the signal in the first path using a first amplifier positioned downstream of the splitter and routing the amplified signal from the first path towards the output;
• defining a second path between the input and the output of the amplifier arrangement, the second path including said splitter;
• providing an amplifier and a channel routing device in the second path downstream of said splitter;
• and
• routing the amplified signal from the second path towards the output.