Femtosecond laser and swift-ion damage in lithium niobate: A comparative analysis

Abstract

A first principles study of the lattice stability of diamond-structure semiconductors under intense laser irradiation J. Appl. Phys. 113, 023301 (2013) High-order sideband generation in bulk GaAs Appl. Phys. Lett. 102, 012104 (2013) Defect mediated reversible ferromagnetism in Co and Mn doped zinc oxide epitaxial films J. Appl. Phys. 112, 113917 (2012) Time-domain sampling of x-ray pulses using an ultrafast sample response Appl. Phys. Lett. 101, 243106 (2012) The effects of vacuum ultraviolet radiation on low-k dielectric films App. Phys. Rev. 2012Rev. , 12 (2012 Additional information on J. Appl. Phys. Relevant damage features associated with femtosecond pulse laser and swift-ion irradiations on LiNbO 3 crystals are comparatively discussed. Experiments described in this paper include irradiations with repetitive femtosecond-laser pulses ͑800 nm, 130 fs͒ and irradiation with O, F, Si, and Cl ions at energies in the range of 0.2-1 MeV/amu where electronic stopping power is dominant. Data are semiquantitatively discussed by using a two-step phenomenological scheme. The first step corresponds to massive electronic excitation either by photons ͑primarily three-photon absorption͒ or ions ͑via ion-electron collisions͒ leading to a dense electron-hole plasma. The second step involves the relaxation of the stored excitation energy causing bond breaking and defect generation. It is described at a phenomenological level within a unified thermal spike scheme previously developed to account for damage by swift ions. A key common feature for the two irradiation sources is a well-defined intrinsic threshold in the deposited energy density U th required to initiate observable damage in a pristine crystal: U th Ϸ 1.3ϫ 10 4 −2ϫ 10 4 J / cm 3 for amorphization in the case of ions and U th Ϸ 7 ϫ 10 4 J / cm 3 for ablation in the case of laser pulses. The morphology of the heavily damaged regions ͑ion-induced tracks and laser-induced craters͒ generated above threshold and its evolution with the deposited energy are also comparatively discussed. The data show that damage in both types of experiments is cumulative and increases on successive irradiations. As a consequence, a certain incubation energy density has to be delivered either by the ions or laser photons in order to start observable damage under subthreshold conditions. The parallelism between the effects of laser pulses and ion impacts is well appreciated when they are described in terms of the ratio between the deposited energy density and the corresponding threshold value.

Nanostructure evolution in joining of Al and Fe nanoparticles with femtosecond laser irradiation

“…The amorphous and partially crystalline phases can be formed due to the atomic intermixing properties of these two dissimilar materials. Garcia-Navarro et al 22 have discussed the damage caused by femtosecond laser irradiation using a two-step phenomenological scheme. The results indicate that the first stage involves strong electronic excitation leading to the formation of a high density electron-hole plasma, while the second stage involves the relaxation of the stored excitation energy of electrons by transfer to the lattice resulting in bond breaking, and defect generation.…”

Alternative approaches to electronic damage by ion‐beam irradiation: Exciton models

“…Extensive effort has been carried out in last years to understand the mechanisms of damage by high electronic energy deposition with particular attention to the formation of tracks. The mechanisms, which, indeed, rely on electronic processes are not yet fully understood and are expected to be related to those operating under high‐power femtosecond laser pulse irradiations . One should, first, remark that the local energy deposition in a single impact event may reach more than 10 22 eV cm −3 , with rates of 10 34 eV cm −3 s −1 , which are orders of magnitude higher than those obtained with other conventional sources (light, X‐rays, and electrons).…”

Nanostructure formation on lithium niobate surfaces by high-repetition rate sub-15-fs near-infrared laser pulses

“…Using amplified 800-nm Ti:Sapphire laser light of pulse length 50 -130 fs at pulse energies in the microjoule range ablated features of a few micrometers up to tens of micrometers in size were generated [5,12,13]. Spots of approximately 1 µm in diameter were generated using 300-fs pulses [14], and subwavelength holes of 80 -250 nm in diameter resulted from illumination by 150-fs pulses [15].…”

“…Focused ion beam etching allows for the manufacture of nanoscale structures, but is inherently very slow [4]. Alternatively, laser processing has emerged as a structuring method [3,5,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Micrometer-size patterns were formed by mask-projection using 248-nm nanosecond-pulsed KrF laser light [7,8].…”