Ultrashort-pulse laser ablation of indium phosphide in air

Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses

“…11 Very recently, the formation of subwavelength-sized ripples has been reported by Borowiec and Haugen for the irradiation of various compound semiconductors, including InP by 50-130 fs laser pulses at several wavelengths (800, 1300, and 2100 nm) and for typically between 1 and 100 pulses per spot. 14 Near the ablation threshold, these authors reported the formation of highspatial-frequency LIPSS (HSFL), with lateral periods 4.2-5.1 times smaller than the wavelength of the incident light, only when the laser photon energy is below the band-gap energy of the target materials.…”

“…In a previous study it has been shown that in InP, irradiated under similar experimental conditions ( 0 = 0.58 J / cm 2 , N = 100), the ablated area also increases logarithmically with N which is a consequence of damage accumulation effects. 11 After reaching a nearly constant value ͑N =8-20͒, the Fourier amplitudes fall off again when the LSFL peak starts to blur out ͑N Ͼ 20-30͒. Simultaneously, at those high pulse numbers, a characteristic pattern of grooves which is perpendicular to the ripple structures starts to develop from the center of the irradiated regions [see the starshaped symbols in Fig.…”

“…2,[4][5][6] With respect to the irradiation with femtosecond laser pulses, ripples with spatial periods close to the wavelength have been reported on various absorbing materials such as metals, 7 ceramics, 8,9 and semiconductors. [10][11][12][13] Interestingly, in most of these cases the ripple period is somewhat smaller than the wavelength and their orientation is mostly perpendicular to the electric-field vector. These nearly wavelengthsized ripples have been mainly observed for moderate pulse numbers (N smaller than ϳ100) at fluences slightly above the single-pulse ablation threshold of the material.…”

Time- and space-resolved dynamics of ablation and optical breakdown induced by femtosecond laser pulses in indium phosphide

“…1 Recently, the behavior of this material upon irradiation with femtosecond laser pulses has been studied by different groups using complementary in situ [2][3][4] and ex situ techniques. [5][6][7][8][9][10][11][12][13] During the course of these experiments, a particular morphological feature has been observed by two different groups in the singlepulse ablation regime whose origin has not been unambiguously identified yet. 6,11 In a previous publication, some of us reported a characteristic permanent ring pattern in the ablation craters which exhibited a threshold behavior and which was related to a local recrystallization process of the residual melt pool on the semiconductor surface.…”

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

“…This result can be formulated in an equivalent alternative way: the single-pulse threshold fluence for ablation decreases with the number of prior laser pulses ͑ac-cumulated fluence͒ applied to the same spot. In fact, it is well documented 19,36,37 for several dielectric and semiconductor crystals that the damage threshold under femtosecond-pulsed laser irradiation decreases with the number of pulses. All those features are again indicative of the cumulative character of the damage.…”