Electronic structure calculations of an oxygen vacancy in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">K</mml:mi><mml:msub><mml:mi mathvariant="normal">H</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi mathvariant="normal">P</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>

Liu, C. S.; Hou, Chunju; Kioussis, Nicholas; Demos, Stavros G.; Radousky, Harry B.

doi:10.1103/physrevb.72.134110

Cited by 60 publications

(39 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From this study, we conclude that a non-negligible density of SLGs exist in both materials, or are rapidly created in the course of interaction. This observation is consistent with first principles DFT calculations showing that oxygen or hydrogen vacancies induce SLG [10,11]. A schematic illustration of the according band structure and of the two excitation-relaxation processes is provided by Fig.…”

Section: Resultssupporting

confidence: 88%

“…This second process is intensity and isotope-dependent and may only need one photon to promote electrons from the states close to the CB. Here, the thermalized electrons and holes move independently of each other and both the electrons and holes can be stabilized in a variety of positive and negative traps [10,11,16] [7]. It is worth noting that the latter reaction can take place only when the crystalline lattice is relaxed, i.e.…”

Section: Resultsmentioning

confidence: 99%

“…The LID of (D)KDP crystals have been studied both experimentally and theoretically in the nanosecond timescale, see for example [8][9][10][11][12][13][14][15]. The evolution of the fluence required to reach a given damage level with respect to the laser wavelength shows a particular feature: this fluence evolves by successive plateaus [8] which can be explained by introducing States Located in the band Gap (hereafter referred to as SLG) [16,17].…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Carrier dynamics in KDP and DKDP crystals illuminated by intense femtosecond laser pulses

et al. 2011

View full text Add to dashboard Cite

The dynamics of electrons and holes in potassium dihydrogen phosphate (KH 2 PO 4 or KDP) crystals and its deuterated analog (KD 2 PO 4 or DKDP) induced by femtosecond laser pulses is investigated at λ = 800nm. To do so, experiments based on a femtosecond time-resolved interferometry technique have been carried out. It is shown that two relaxation dynamics exist in KDP and DKDP crystals. In particular, it appears that one dynamics is associated with the migration of proton/deuteron in the crystalline lattice. Both of the dynamics correspond to physical mechanisms for which the multiphoton order required to promote valence electrons to the conduction band is lower than the one of a defect-free crystal. These results suggest the presence of states located in the band gap that may be due to the presence of defects existing before any laser illumination or created in the course of interaction. In order to interpret the experiments, a model based on a system of rate equations has been developed. Modeling results are in good agreement with the experimental data, and allow one to obtain fundamental physical parameters governing the laser-matter interaction as multiphoton absorption cross sections, capture cross sections, recombination times, and so forth. Finally, it will be shown how these results can be used to the understanding of laser-induced damage by nanosecond pulses in inertial confinement fusion class laser aperture.

show abstract

Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Carrier dynamics in KDP and DKDP crystals illuminated by intense femtosecond laser pulses

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The existence of point defects on the other hand increases the randomness of the crystal. So in some parts of area, the point defects stay close together and the concentration in this area is in an order of 10 −2 [24], which is quite higher than the average concentration. First principle calculation for hydrogen point defects in KDP has found that the band gap for the neutral interstitial H and positive charged H vacancy are greatly reduced to 2.6 and 2.5eV [13,14], which is smaller than photon energy of 355nm laser.…”

Section: Resultsmentioning

confidence: 98%

Transmittance increase after laser conditioning reveals absorption properties variation in DKDP crystals

Zhao

et al. 2012

Opt. Express

View full text Add to dashboard Cite

By taking multiple measurements of transmittance before and after laser conditioning in DKDP crystals, we found that the transmittance was increased by 0.05%~0.4% through laser conditioning with maximum fluence 6J/cm 2 , and then decreased by about 0.1% after subsequent higher fluence conditioning. Variation of scattering intensity and absorber density, the two major factors leading to transmittance change, was monitored by on-line and off-line detection systems. The transmittance decrease was attributed to laser damage scattering, and the increase was derived from reduction of absorbers. Moreover, the absorption was reduced further at higher conditioning fluence. Based on the above analysis, the heating process during laser exposure was analyzed in the time domain, and a local rapid-rising and slow-cooling process was confirmed to reduce defect concentration, which can improve laser damage resistance and increase the transmittance.

show abstract

“…First, one can consider point defects, corresponding to hydrogen or oxygen atoms as interstitial atoms or vacancies in the crystalline lattice. [10][11][12] These can be associated with (PO 3 ) −13 or (HPO 4 ) − groups. 8,9,14 Since simple considerations based on heat transfer 5,15 have demonstrated that the precursor defect size ranges between roughly 10 nm and 100 nm in order to produce a sufficiently high temperature, only a cluster of point defects can satisfy the precursor defect size requirement.…”

Section: Introductionmentioning

confidence: 98%

Modeling laser conditioning of KDP crystals

Duchateau

2009

SPIE Proceedings

View full text Add to dashboard Cite

When potassium dihydrogen phosphate crystals (KH 2 PO 4 or KDP) are illuminated by multi-gigawatt nanosecond pulses, damages may appear in the crystal bulk. One can increase damage resistance through a conditioning that consists in carrying out a laser pre-exposure of the crystal. The present paper addresses the modeling of laserinduced conditioning of KDP crystals. The method is based on heating a distribution of defects, the cooperation of which may lead to a dramatic temperature rise. The conditioning is assumed to be due to a decrease in the defect absorption efficiency. Two scenarios associated with various defect natures are proposed and these account for certain of the observed experimental facts. For instance, in order to improve the crystal resistance to damage, one needs to use a conditioning pulse duration shorter than the testing pulse. Also, a conditioning scenario based on the migration of point (atomic-size) defects allows the reproduction of a logarithmic-like evolution of the conditioning gain with respect to the number of laser pre-exposures. Moreover, this study aims at refining the knowledge regarding the precursor defects responsible for the laser-induced damage in KDP crystals. Within the presented modeling, the best candidate permitting the reproduction of major experimental facts is comprised of a collection of one-hundred-nanometer structural defects associated with point defects as for instance cracks and couples of oxygen interstitials and vacancies.

show abstract

Electronic structure calculations of an oxygen vacancy inKH2PO4

Cited by 60 publications

References 28 publications

Carrier dynamics in KDP and DKDP crystals illuminated by intense femtosecond laser pulses

Carrier dynamics in KDP and DKDP crystals illuminated by intense femtosecond laser pulses

Transmittance increase after laser conditioning reveals absorption properties variation in DKDP crystals

Modeling laser conditioning of KDP crystals

Contact Info

Product

Resources

About