Ultrafast change in optical properties of gallium: the evidence of a new transient state of matter

Author

Gamaly, E.G. ; Rode, A.V.

Author_Institution

Dept. of Appl. Math., Australian Nat. Univ., Canberra, ACT, Australia

fYear

2000

fDate

10-15 Sept. 2000

Abstract

Summary form only given. 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 /spl sim/60%, typical for crystalline /spl alpha/-Ga, to 70-75% in /spl sim/2 ps has been measured by the probe-pump technique using Ti:sapphire laser (150 fs, 800 nm). After the initial 2-ps rise the reflectivity approaches the value characteristic for liquid Ga of /spl sim/85% in more than 100 ps. The developed self-consistent theoretical model considers 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.

Keywords

gallium; high-speed optical techniques; laser deposition; optical films; optical pumping; reflectivity; skin effect; 100 ps; 150 fs; 2 ps; 800 nm; Ga; SiO/sub 2/; Ti:sapphire laser; conduction electrons; crystalline /spl alpha/-Ga; fused silica substrates; gallium; gallium films; induced transient changes; laser-gallium interaction process; liquid Ga; optical properties; probe-pump technique; pulsed laser deposition; rapid reflectivity rise; reflectivity; self-consistent theoretical model; transient matter state; ultrafast change; Absorption; Crystallization; Gallium; Heating; Laser modes; Laser theory; Optical films; Reflectivity; Silicon compounds; Ultrafast optics;

fLanguage

English

Publisher

ieee

Conference_Titel

Lasers and Electro-Optics Europe, 2000. Conference Digest. 2000 Conference on

Conference_Location

Nice

Print_ISBN

0-7803-6319-1

Type

conf

DOI

10.1109/CLEOE.2000.910415

Filename

910415