Synthesis of arbitrary pulse waveforms in QCL-seeded ns-pulse CO_2 laser for optimization of an LPP EUV source

One of the unique features of the quantum-cascade-laser-seeded, nanosecond-pulse CO2 laser, invented for the purpose of generation of extreme UV by laser-produced-plasma, is a robust synthesis of arbitrary pulse waveforms. In the present Letter we report on experimental results that are, to our best knowledge, the first demonstration of such functionality obtainable from nanosecond-pulse CO2 laser technology. An online pulse duration adjustment within 10–40 ns was demonstrated, and a few exemplary pulse waveforms were synthesized, such as “tophat,” “tailspike,” and “leadspike” shapes. Such output characteristics may be useful to optimize the performance of LPP EUV source.