Enhanced transmissivity in fog irradiated by CO2 laser pulses

Experiments were performed to characterize alterations in the transmissivity of an aerosol irradiated with an intense burst from a CO2 laser. The changes in the optical properties of the aerosol are a function of the kinetic and dynamic effects which occur as the droplets explode. Wavelengths of 0.63 and 10.6 microns were employed in heating the aerosol at a rate of up to 10 billion K/sec. The data indicated that majority of the liquid evaporated as the droplets exploded. The time to vaporization was modeled numerically in terms of the mass of vapor produced by explosive boiling and the mass of the droplet. The breakup occurs during passage of the leading edge of the laser beam, leaving secondary particles which are to a high degree transparent to IR and visible wavelengths.