Optical fiber amplifier comprising an embedded filter and a control method with improved feedforward control performance

摘要

An optical amplifier with improved transient performance has two amplifier stages and a gain flattening filter-inserted between the amplifier stages. A control unit generates a pump control signal for a common pump source pumping both amplifier stages. The pump control signal has a feed-forward component and a feedback component. After a drop of channels the feed-forward control circuit is responsible for the transient performance and fast gain stabilization. The characteristic of the gain flattening filter is taken into account in calculating an optimum feed-forward control signal.

主权项

1. An optical fiber amplifier with improved transient performance, comprising:
a first amplifier stage receiving an amplifier input signal and a second amplifier stage connected in series with said first amplifier stage and outputting an amplifier output signal; an optical gain flattening filter inserted between said first and second amplifier stages; at least one pump source generating a pump signal; a control unit connected to said pump source and determining a power of the pump signal, said control unit having: a correction parameter calculation unit receiving measured power levels of a filter input measuring signal and a filter output measuring signal representing measured input and output power levels of said optical gain flattening filter, determining correction parameters from at least the filter measuring signals according to filter attenuation values; and a feed-forward control circuit receiving an input measuring signal derived from an optical amplifier input signal and a correction parameter for calculating a feed-forward control signal acting on the power of said pump signal according to the input power of the amplifier input signal and the correction parameter.