Abstract

When the alkali-metal atoas¹ or nolecuies² mixed with hydrogen molecules are excited by laser light to some highly excited state, alkali- hydride molecules are efficiently produced and micron-size particles are formed by their condensation. Since the produced particles are white crystals and their fall From the laser beam by the gravity force can be seen through eyes, they are called laser snow In addition, thermodynamical consideration shows that, at a relatively high temperature, the environmental gases are expected to be cooled down by evaporation of hydrogen gas from the particles,³ as in the natural snow.

© 1988 Optical Society of America