WDM transmitter

An optical transmitter for a WDM system having multiple WDM channels comprising:

• a pump laser array of up to M pump lasers for producing respective pump beams;
• a M×N multiplexer having M inputs and N outputs, the M inputs being connected to receive the pump beams from respective ones of the pump lasers, wherein the multiplexer is subdivided into a plurality of modules, wherein each configured so that a pump beam received at any one of the inputs of the multiplexer associated with that module is internally routed to all of the outputs of that module;
• and
• a fiber laser array of up to N fiber lasers operable to emit at respective wavelengths λ, λ2 . . . λN for respective ones of the multiple WDM channels, the N outputs of the multiplexer being connected to pump respective ones of the up to N fiber lasers.

An optical transmitter for a WDM system having multiple WDM channels comprising:

• a pump laser array of up to M pump lasers for producing respective pump beams;
• a M×N multiplexer having M inputs and N outputs, the M inputs being connected to receive the pump beams from respective ones of the pump lasers;
• a fiber laser array of up to N fiber lasers operable to emit at respective wavelengths 80 , λ2 . . . λN for respective ones of the multiple WDM channels, the N outputs of the multiplexer being connected to pump respective ones of the up to N fiber lasers;
• and
• a power monitoring device arranged to measure power at a point in the transmitter after the multiplexer and a feedback control device connected to control the pump lasers responsive to the power measured by the power monitoring device.

An optical transmitter for a WDM system having multiple WDM channels comprising:

• a pump laser array of up to M pump lasers for producing respective pump beams;
• a M×N multiplexer having M inputs and N outputs, the M inputs being connected to receive the pump beams from respective ones of the pump lasers;
• and
• an optical amplifier array of up to N optical amplifiers, the N outputs of the multiplexer being connected to pump respective ones of the up to N optical amplifiers, the optical amplifiers each having an input for receiving a signal to be amplified.