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 μm with a specially designed non-aberrational objective, a focal spot of approximately 40 μm diameter could be obtained, with the waist length being 230−280 μm. The measured parameters give an idea of the size of a laser plasma generated by this beam on a Xe gas microjet.