Laser-Induced Modification Of Energy Bands Of Transparent Solids

Journal Article · Fri Oct 08 00:00:00 EDT 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3507096· OSTI ID:21426581

Gruzdev, Vitaly ^[1]

---

1. Department of Mechanical and Aerospace Engineering, College of Engineering University of Missouri, Columbia, MO 65211 (United States)

Laser-induced variations of electron energy bands of transparent solids significantly affect the initial stages of laser-induced ablation (LIA) influencing rates of ionization and light absorption by conduction-band electrons. We analyze fast variations with characteristic duration in femto-second time domain that include: 1) switching electron functions from bonding to anti-bonding configuration due to laser-induced ionization; 2) laser-driven oscillations of electrons in quasi-momentum space; and 3) direct distortion of the inter-atomic potential by electric field of laser radiation. Among those effects, the latter two have zero delay and reversibly modify band structure taking place from the beginning of laser action. They are of special interest due to their strong influence on the initial stage and threshold of laser ablation. The oscillations modify the electron-energy bands by adding pondermotive potential. The direct action of radiation's electric field leads to high-frequency Franz-Keldysh effect (FKE) spreading the allowed electron states into the forbidden-energy bands. FKE provides decrease of the effective band gap while the electron oscillations lead either to monotonous increase or oscillatory variations of the gap. We analyze the competition between those two opposite trends and their role in initiating LIA.

• OSTI ID: 21426581
• Journal Information: AIP Conference Proceedings, Vol. 1278, Issue 1; Conference: International symposium on high power laser ablation 2010, Santa Fe, NM (United States), 18-22 Apr 2010; Other Information: DOI: 10.1063/1.3507096; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABLATION
ABSORPTION
BINDING ENERGY
CHEMICAL BONDS
ELECTRIC FIELDS
ELECTRONIC STRUCTURE
ELECTRONS
ENERGY GAP
ENERGY LEVELS
INTERATOMIC FORCES
IONIZATION
LASER RADIATION
OSCILLATIONS
POTENTIALS
SOLIDS
VARIATIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY
FERMIONS
LEPTONS
RADIATIONS
SORPTION