Optical properties of laser erosion flares in plasma

Plasma flares caused by eroding laser radiation are studied for the purpose of determining the transient characteristics and the space profiles of their optical properties. The plasma flare produced by erosion of the target and propagating against the laser beam was probed with regular radiation pulses. Large particles of the target material (with geometric dimensions larger than the radiation wavelength) within the probed flare zone, indicating almost equal scattering coefficients and almost equal absorption coefficients at both eroding and probing laser wavelengths. They also reveal direct shielding of the eroding laser radiation by erosion products, most effectively at the target surface.