Patent ID: 6882456

Claim:
A pulse shaping apparatus for shaping an input optical pulse into an output optical pulse having substantially constant optical power, the apparatus comprising: a modulator which acts upon the input optical pulse under the control of a control signal to provide the output optical pulse; and control signal means for generating the control signal, said control signal means including a sampling means for sampling a portion of the output optical pulse and generating a sample signal corresponding to optical power of the output optical pulse, and means for generating the control signal for the modulator in dependence upon the value of the sample signal; wherein, the modulator acts on the input optical pulse before the sampling means samples the output optical pulse; the apparatus further includes a digitizing means a memory means, a processing means and a digital to analog converting means; the sample signal is digitized and the digitized sample signal is stored in the memory means; the processing means calculates a plurality of feedback values for the digitized sample signal, which feedback values are converted to an analog feedback signal by the digital to analog converting means; and the analog feedback signal is used as the control signal for the modulator.