Laser air plasma expansion by microwaves

Ikeda, Yuji*; Soriano, J. K.*; Oba, Hironori; Wakaida, Ikuo

Applied Optics, 62(31), p.8434 - 8441, 2023/10

https://doi.org/10.1364/AO.503682

Utilizing micro-lasers and microwaves, the impact of microwaves on the expansion of air plasma was examined. Microwaves was applied to the air plasma generated by a micro-laser, the plasma growth image was visualized and emissions spectra using by a high-resolution spectrometer was observed, and temperature changes and electron density was analyzed. A 400-fold increase in plasma volume due to microwave enhancement, even though the micro-laser operated at a modest energy level of 1 mJ was observed. Although a slight change in electron temperature was observed during microwave irradiation, it was pointed towards the ability of microwaves to sustain plasma characteristics over time. These will be suggested that the microwave application potentially improves the analytical performance of laser-induced breakdown spectroscopy (LIBS).