Abstract

The fundamental reasons behind the rapid reflectivity rise of gallium films deposited on fused silica substrates have been considered in detail. The increase of reflectivity from the value of ~60%, typical for crystalline α-Ga, to 70-75% in ~2 ps has been measured by the probe-pump technique using Ti-Sapphire laser (150 fs, 800 nm) [1]. After the initial 2-ps rise the reflectivity approaches the value characteristic for liquid Ga of ~85% in more than 100 ps. The developed self-consistent theoretical model consider the laser-gallium interaction process, absorption, and heating of the conduction electrons. The induced transient changes of the optical properties of gallium layer are in qualitative agreement with the experimental data.

© 2000 IEEE