TY - GEN

T1 - Quantized behavior of the LIDT in the fs-range in dielectric layers

AU - Jupé, Marco

AU - Jensen, Lars

AU - Starke, Kai

AU - Ristau, Detlev

AU - Melninkaitis, Andrius

AU - Grigonis, R.

AU - Sirutkaitis, Valdas

PY - 2005/2/21

Y1 - 2005/2/21

N2 - In comparison to studies at longer pulse regimes, investigations of laser induced damage threshold indicate a contrary behavior on the fs-scale for the dielectric coatings. In general, experiments reveal an electronic cause of the damage. The strong correlation of theoretical calculations with experimental data of laser induced damage thresholds for quartz verifies this assumption. Consequently, the characteristic function of the wavelength dependence of the damage threshold differs in this range from the classical behavior. The quantized structure of the electronic transition leads to a typical step function of the LIDT in dependence on the band gap energy of the materials. Hence, the step should be observed between energy levels from n to n+1 electron ionization. In detail, the probability for the transition of the electron from the valence band to the conduction band changes abruptly. In an international cooperation with the University of Vilnius the wavelength dependence of the LIDT was investigated for dielectric coatings of TxSi1-xO 2as a function of the stoichiometry. The measurements were performed for a wavelength range from 600 to 800 nm and at a pulse duration of 130 fs by using an OPA laser system. The step from two photon to three photon ionization was measured. The assumption of the mentioned behavior of the fs-damage was proven. For different concentrations of silicon and titanium in the oxide, the electronic structure of the material changes. The experiments have shown an increasing gap energy and LIDT for a high content of silica.

AB - In comparison to studies at longer pulse regimes, investigations of laser induced damage threshold indicate a contrary behavior on the fs-scale for the dielectric coatings. In general, experiments reveal an electronic cause of the damage. The strong correlation of theoretical calculations with experimental data of laser induced damage thresholds for quartz verifies this assumption. Consequently, the characteristic function of the wavelength dependence of the damage threshold differs in this range from the classical behavior. The quantized structure of the electronic transition leads to a typical step function of the LIDT in dependence on the band gap energy of the materials. Hence, the step should be observed between energy levels from n to n+1 electron ionization. In detail, the probability for the transition of the electron from the valence band to the conduction band changes abruptly. In an international cooperation with the University of Vilnius the wavelength dependence of the LIDT was investigated for dielectric coatings of TxSi1-xO 2as a function of the stoichiometry. The measurements were performed for a wavelength range from 600 to 800 nm and at a pulse duration of 130 fs by using an OPA laser system. The step from two photon to three photon ionization was measured. The assumption of the mentioned behavior of the fs-damage was proven. For different concentrations of silicon and titanium in the oxide, the electronic structure of the material changes. The experiments have shown an increasing gap energy and LIDT for a high content of silica.

UR - http://www.scopus.com/inward/record.url?scp=18744380698&partnerID=8YFLogxK

U2 - 10.1117/12.597993

DO - 10.1117/12.597993

M3 - Conference contribution

AN - SCOPUS:18744380698

SN - 0-8194-5607-1

T3 - Proceedings of SPIE - The International Society for Optical Engineering

SP - 53

EP - 60

BT - Laser-Induced Damage in Optical Materials: 2004

PB - SPIE

CY - Bellingham

T2 - 36th Annual Boulder Damage Symposium

Y2 - 20 September 2004 through 22 September 2004

ER -