Patent ID: 10186827

Abstract:
Systems, methods, and apparatus, including non-transitory computer-readable storage medium, for amplifying pulsed laser radiation in an EUV laser driver are provided. An example EUV laser driver includes a beam source configured to produce the pulsed laser radiation with at least one laser frequency, an amplifier arrangement with at least one optical amplifier for amplifying the pulsed laser radiation, the at least one optical amplifier having a frequency-dependent gain with a maximum gain at a maximum frequency, at least one frequency shifter configured to produce a frequency shift for the laser frequency of the pulsed laser radiation relative to the maximum frequency, and a controller configured to set the frequency shift such that a gain of the at least one optical amplifier for the pulsed laser radiation is reduced to less than a percentage, e.g., 90%, 70%, or 50%, of the maximum gain.