Ablation of crystalline oxides by infrared femtosecond laser pulses

Watanabe, Fumiya; Cahill, David G.; Gundrum, Bryan; Averback, Robert S

doi:10.1063/1.2358001

Cited by 17 publications

(12 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The gentle ablation fluence threshold observed is consistent with the value in [12]. Previous works on ultrafast laser structuring of sapphire show crater profiles with similar fluence-dependent strong and gentle ablation features upon irradiation with sub-200-fs pulses using both single- [17,18,34] and multiple-pulse irradiation [9,35].…”

Section: Resultssupporting

confidence: 86%

Controlling ablation mechanisms in sapphire by tuning the temporal shape of femtosecond laser pulses

Hernández-Rueda¹,

Siegel²,

Galvan-Sosa³

et al. 2014

J. Opt. Soc. Am. B

View full text Add to dashboard Cite

We have analyzed the influence of the temporal pulse shape on femtosecond (fs) laser-induced surface ablation processes in sapphire. To this end, single transform-limited (TL), stretched, and third-order-dispersion (TOD) shaped fs pulses have been used, while the dynamics of the interaction were analyzed by fs-resolved microscopy and correlated with plasma emission intensity and crater morphology. The modification of the pulse shape enables changing the ablation mechanism from a strong, thermally mediated ablation process to a gentle ablation process mediated by Coulomb explosion (CE), with respective ablation depths of 100-200 nm and 5-10 nm. Analysis of the transient optical response allows direct comparison of the transient plasma carrier densities involved, observing comparable peak values for both processes. For strong ablation induced by TL pulses, a direct relation between plasma density and local ablation depth is found, but this does not hold for the CE-mediated process observed for TOD-shaped pulses. For TOD-shaped pulses at very high fluence, a different ablation mechanism involving explosive boiling is identified. This mechanism leads to the formation of deep craters with reduced lateral extension and steep walls. This amount of control over the ablation mechanisms by a simple selection of the pulse shape should be of interest for new surface structuring approaches.

show abstract

Section: Resultssupporting

confidence: 86%

Controlling ablation mechanisms in sapphire by tuning the temporal shape of femtosecond laser pulses

Hernández-Rueda¹,

Siegel²,

Galvan-Sosa³

et al. 2014

J. Opt. Soc. Am. B

View full text Add to dashboard Cite

show abstract

“…[16][17][18] In the near-threshold ablation regime, which for STO (Ref. 19) starts above 1.2 J/cm 2 , the major form of damage observed following ablation involves the formation of dislocation substructures immediately beneath the pulsed region. During irradiation by a femtosecond pulse (typically 150 fs for a Ti:Sapphire laser), the photon energy is absorbed by the electronic structure to 20-500 nm within the sample surface.…”

Section: Introductionmentioning

confidence: 99%

Dislocation injection in strontium titanate by femtosecond laser pulses

Titus

Echlin

Gumbsch

et al. 2015

Journal of Applied Physics

View full text Add to dashboard Cite

Femtosecond laser ablation is used in applications which require low damage surface treatments, such as serial sectioning, spectroscopy, and micromachining. However, dislocations are generated by femtosecond laser-induced shockwaves and consequently have been studied in strontium titanate (STO) using transmission electron microscopy (TEM) and electron backscatter diffraction analysis. The laser ablated surfaces in STO exhibit dislocation structures that are indicative of those produced by uniaxial compressive loading. TEM analyses of dislocations present just below the ablated surface confirm the presence of < 110 > dislocations that are of approximately 35 degrees mixed character. The penetration depth of the dislocations varied with grain orientation relative to the surface normal, with a maximum depth of 1.5 mu m. Based on the critical resolved shear stress of STO crystals, the approximate shockwave pressures experienced beneath the laser irradiated surface are reported

show abstract

“…Films are grown epitaxially and are nearly single crystalline. 23 Attenuation is not limited by metal film grains or Cr/sapphire interface scattering but governed by intrinsic damping processes. 24,25 The thickness of the Cr probe films is d probe ϳ 20 nm while the Cr transducers at the pump side are d pump ϳ 100 nm thick.…”

Section: B Samples and Preparationmentioning

confidence: 99%

Time-resolved interferometric detection of ultrashort strain solitons in sapphire

Capel

Dijkhuis

2010

Phys. Rev. B

View full text Add to dashboard Cite

We study one-dimensional nonlinear propagation of high-amplitude acoustic waves in sapphire, for various sample temperatures, sample thicknesses, and pump fluences. Strain waves are generated in a 100-nm-thick chromium film and launched into the sapphire. For temperatures Ͻ60 K, damping can be neglected and propagation is dominated by the nonlinear and dispersive properties of the sapphire substrate. An interferometric technique is used to detect the wave on an epitaxially grown ϳ20-nm-thick Cr film at the opposite side of the sample. At the lowest temperature of 18 K, a train of up to seven solitons is detected in sapphire for a pump fluence of 11 mJ/ cm 2 . From the soliton amplitudes and velocities, we infer soliton temporal and spatial widths as short as 200 fs and 2 nm. A theoretical analysis based on numerical solution of the Korteweg-de Vries-Burgers equation yields excellent agreement to all experiments presented. Deviations to the direct theoretical result can be explained by pump intensity variations, affecting the ͑nonlinear͒ propagation properties.

show abstract

Ablation of crystalline oxides by infrared femtosecond laser pulses

Cited by 17 publications

References 49 publications

Controlling ablation mechanisms in sapphire by tuning the temporal shape of femtosecond laser pulses

Controlling ablation mechanisms in sapphire by tuning the temporal shape of femtosecond laser pulses

Dislocation injection in strontium titanate by femtosecond laser pulses

Time-resolved interferometric detection of ultrashort strain solitons in sapphire

Contact Info

Product

Resources

About