Controlling a laser source to compensate for change in pulse length by adjusting cycle number of an amplifier

A method comprising:

• emitting, by a laser source, one or more laser pulses, the laser source comprising an amplifier;
• changing, by one or more optical elements, a pulse length of the one or more laser pulses, the one or more optical elements comprising a focusing objective;
• measuring, by a monitoring device, the pulse length of the one or more laser pulses to detect the change in the pulse length, the monitoring device coupled to or disposed within the focusing objective;
• receiving, at a control computer, the measured pulse length from the monitoring device;
• determining, by the control computer, one or more laser parameters that compensate for the change in the pulse length, the one or more laser parameters comprising a cycle number of the amplifier;
• and
• controlling, by the control computer, the laser source according to the one or more laser parameters by instructing the laser source to adjust the cycle number to compensate for the detected change in the pulse length.