Surface morphology and phase transformations of femtosecond laser-processed sapphire

AbstractSilicon surface morphology induced by a femtosecond laser pulse at near-threshold fluences in water environment is investigated by means of atomic-force microscopy (AFM). With increasing fluence, the silicon surface transforms into nanoscale ring-shaped and blister structures, as well as smooth and nanostructured microcraters with a minimum depth of 1 nm. The formation of starlike patterns imprinted at the surface of microcraters at fluences above the ablation threshold is observed.

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Machining millimeter-scale deep holes in SiCf/SiC material using femtosecond laser filamentation effect

Materials Science Advanced Composite Materials ◽

10.18063/msacm.v2i1.748 ◽

2018 ◽

Vol 2 (3) ◽

Author(s):

Jie Zhao 1,2 ◽

Wenjun Wang 1,2 ◽

Ruijia Wang 1,2 ◽

Jianlei Cui 1,2

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Femtosecond Laser ◽

Surface Morphology ◽

Peak Power ◽

Processing Time ◽

Ablation Threshold ◽

Focus Position ◽

Laser Focus ◽

Scanning Electron

A 3.5 mm thick SiCf/SiC material was drilled in air environment using a femtosecond laser filament effect. The surface morphology of deep micropores was observed by scanning electron microscopy and the depth and profile of the pores were observed using μm-CT. The variation of entrance diameter, exit diameter and depth variation with laser focus position and processing time was further analyzed. The results showed that as the processing time of femtosecond laser increases, the ablation threshold of the material reached saturation. The exit and entrance diameter also stopped increasing and the aperture tend to saturate. The focus entered the interior of the material, allowing the location of the peak power near the surface of the material. So the entrance aperture was of good quality and the exit aperture was round.

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Phase transformations of an InSb surface induced by strong femtosecond laser pulses

Physical Review B ◽

10.1103/physrevb.53.15878 ◽

1996 ◽

Vol 53 (23) ◽

pp. 15878-15884 ◽

Cited By ~ 70

Author(s):

I. L. Shumay ◽

U. Höfer

Keyword(s):

Femtosecond Laser ◽

Phase Transformations ◽

Laser Pulses ◽

Femtosecond Laser Pulses

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Femtosecond Laser-Induced Silicon Surface Morphology in Water

Volume 10: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B, and C ◽

10.1115/imece2008-67923 ◽

2008 ◽

Author(s):

Yukun Han ◽

Cheng-Hsiang Lin ◽

Hai-Lung Tsai

Keyword(s):

Femtosecond Laser ◽

Surface Morphology ◽

Surface Quality ◽

Silicon Wafer ◽

Silicon Surface ◽

Periodic Structures ◽

Industrial Applications ◽

Silicon Surfaces ◽

Wafer Surface ◽

Laser Parameter

This article investigates the use of femtosecond laser induced surface morphology on silicon wafer surface in water confinement. Unlike irradiation of silicon surfaces in the air, there are no laser induced periodic structures, but irregular roughness is formed when the silicon wafer is ablated under water. The unique discovery of a smoothly processed silicon surface in water confinement under certain laser parameter combinations may help improve laser direct micromachining surface quality in industrial applications.

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