A transmitter (TX) for a WDM optical link includes a light source (CS) generating a plurality of discrete lines (EL) with different frequencies (f), a plurality of modulators (FSM, RRM, MZM), each modulator (FSM, RRM, MZM) being configured to modulate one of the discrete lines (EL) according to a data stream (c1-c4), at least one optical amplifier (SOA) configured to simultaneously amplify multiple lines (EL), wherein only a subset of the generated lines (EL) is routed to the optical amplifier (SOA) resp. to each one of the optical amplifiers (SOA). A receiver (RX) for an optical link adapted to work together with the transmitter (TX) is also described. An optical link including the transmitter (TX) and/or the receiver (RX), and a method to operate said link are also described.