a laser processing apparatus , a filter device and a method are used for controlling a pulse laser , which is controllable in terms of its pulse energy and of a temporal triggering of laser pulses , during material processing of an object , in particular during the marking of a plastics - based document . the method includes comparing a pulse energy signal which assumes voltage values , in temporal correlation with a clock signal , which represent a pulse energy for the laser pulses for processing , with a threshold value condition and generating a logic result signal . the clock signal is passed to a gate and controlling the gate using the logic result signal and generating a retrieval signal thereby . an energy control signal is provided which has a voltage according to a specification of a control voltage . the retrieval signal and the energy control signal are used to control the pulse laser .