Measuring geometric parameters of a high-power infrared laser beam near the focus for applications in a laser-plasma short-wave radiation source

Measurements of geometric parameters of a high-power infrared laser beam have been realized by three methods. The obtained results are in a satisfactory agreement with each other. When focusing the beam with wavelength of 1.064 $\mu$m with a specially designed non-aberrational objective, a focal spot of approximately 40 $\mu$m diameter could be obtained, with the waist length being 230–280 $\mu$m. The measured parameters give an idea of the size of a laser plasma generated by this beam on a Xe gas microjet.