摘要 |
<p>The invention describes an optical amplifier with improved transient performance comprising two amplifier stages (4, 9) and a gain flattening filter (6) inserted between these stages. A control unit (17) generates a pump control signal (PCS) for a common pump source (13) pumping both amplifier stages (4, 9). The pump control signal (PCS) has a feedforward component (FCS) and a feedback component (BCS). After a drop of channels the feedforward control circuit (19) is responsible for the transient performance and fast gain stabilisation. The characteristic of the gain flattening filter (6) is taken into account to calculate an optimum feedforward control signal (FCS).</p> |