Experimental Investigation on the Scribing of Sapphire Using UV Laser

2011 ◽  
Vol 121-126 ◽  
pp. 147-151
Author(s):  
Mao Lu Wang ◽  
Yang Wang ◽  
Lei Qin ◽  
Jian Guan
Keyword(s):  
Laser Ablation ◽  
High Hardness ◽  
Scanning Speed ◽  
Laser Pulses ◽  
Wide Bandgap ◽  
Uv Laser ◽  
New Approach ◽  
Wide Bandgap Semiconductor ◽  
Good Surface ◽  
Pulse Energies

Sapphire is an important wide bandgap semiconductor material for developing UV/blue optoelectronic devices, however because of its high hardness and chemical stability; it is mechanically and chemically difficult machine. In this paper, the scribing of sapphire by UV laser pulses is investigated under various conditions of pulse energies, scanning speed and repetition rate. The quality and morphology of the laser ablation of sapphire surface are evaluated by scanning electron microscopy. The mechanism of UV laser ablation of sapphire is discussed. The formation of grooves with high aspect ratio and good surface quality is achieved by selecting appropriate laser parameters. Scribing by pulsed UV laser therefore provide a new approach in the development of sapphire-based devices.

Nanosecond and Femtosecond UV Laser Ablation of CdTe (100): Time-Of-Flight and Angular Distributions

1993 ◽  
Vol 334 ◽  
Author(s):  
P.D. Brewer ◽  
M. Späth ◽  
M. Stuke
Keyword(s):  
Laser Ablation ◽  
High Resolution ◽  
Mass Spectrometer ◽  
Multiphoton Ionization ◽  
Time Of Flight ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Dye Laser ◽  
Angular Distributions ◽  
Uv Laser

AbstractAngularly resolved time-of-flight (TOF) measurements have been used to probe the velocity and angular distributions of Cd atoms and Te2 molecules ejected from CdTe (100) substrates under irradiation by 248 nm nanosecond and sub-picosecond laser pulses. These experiments employ a dye laser TOF mass spectrometer with resonance enhanced multiphoton ionization for sensitive, high resolution detection of the desorbed products. The velocity distributions are well described by Maxwell-Boltzmann distributions for low fluence nanosecond (<60 mJ/cm2) and sub-picosecond (<3.3 mJ/cm2) pulses. Angular flux distributions for nanosecond irradiation are observed to be highly forward peaked about the surface normal, whereas, for sub-picosecond irradiation the distribution approaches cos3θ.

scholarly journals Micropatterning MoS2/Polyamide Electrospun Nanofibrous Membranes Using Femtosecond Laser Pulses

Photonics ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 3 ◽  
Author(s):  
Kelly T. Paula ◽  
Luiza A. Mercante ◽  
Rodrigo Schneider ◽  
Daniel S. Correa ◽  
Cleber R. Mendonca
Keyword(s):  
Laser Ablation ◽  
Composite Nanofibers ◽  
Electrospun Nanofibers ◽  
Scanning Speed ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Spectroscopic Techniques ◽  
Fs Laser ◽  
Nanofibrous Membranes ◽  
Scale Control

The capability of modifying and patterning the surface of polymer and composite materials is of high significance for various biomedical and electronics applications. For example, the use of femtosecond (fs) laser ablation for micropatterning electrospun nanofiber scaffolds can be successfully employed to fabricate complex polymeric biomedical devices, including scaffolds. Here we investigated fs-laser ablation as a flexible and convenient method for micropatterning polyamide (PA6) electrospun nanofibers that were modified with molybdenum disulfide (MoS2). We studied the influence of the laser pulse energy and scanning speed on the topography of electrospun composite nanofibers, as well as the irradiated areas via scanning electron microscopy and spectroscopic techniques. The results showed that using the optimal fs-laser parameters, micropores were formed on the electrospun nanofibrous membranes with size scale control, while the nature of the nanofibers was preserved. MoS2-modified PA6 nanofibrous membranes showed good photoluminescence properties, even after fs-laser microstructuring. The results presented here demonstrated potential application in optoelectronic devices. In addition, the application of this technique has a great deal of potential in the biomedical field, such as in tissue engineering.

scholarly journals Laser and Material Parameter Dependence of the Chemical Modifications in the UV Laser Processing of Model Polymeric Solids

2002 ◽  
Vol 20 (1) ◽  
pp. 1-21 ◽  
Author(s):  
E. Andreou ◽  
A. Athanassiou ◽  
D. Fragouli ◽  
D. Anglos ◽  
S. Georgiou
Keyword(s):  
Laser Processing ◽  
Laser Pulses ◽  
Model Systems ◽  
Critical Parameters ◽  
Major Type ◽  
Uv Laser ◽  
Chemical Modifications ◽  
Good Surface ◽  
Molecular Substrates ◽  
Processing Techniques

Chemical modifications are expected to be the major type of side-effect in the UV laser processing of molecular substrates. For their systematic characterization, studies on polymeric systems consisting of poly(methyl methacrylate) and polystyrene films doped with aromatic dopants exemplifying different degrees of photoreactivity are undertaken. In particular, the dependence of the nature and extent of the modifications on chromophore properties and laser parameters (laser fluence, wavelength, and number of pulses) is examined. The substrate absorptivity and the number of employed laser pulses turn out to be the critical parameters in determining the quantity and nature of photoproducts that remain in the substrate. The implications of these results for the optimisation of laser processing of molecular/organic solids are discussed. It is suggested that the importance of employing relatively strongly absorbed wavelengths in laser processing may relate, besides the efficient etching and good surface morphology, to the minimization of the chemical modifications. In contrast, irradiation with successive laser pulses is indicated to be highly disadvantageous for the chemical integrity of the substrate. In all, the study of such model systems appears to be most appropriate for establishing criteria for the systematic optimisation of laser processing techniques of molecular substrates.

Nanosecond Laser Ablation of Silicon Carbide at Infrared Wavelength

2010 ◽  
Author(s):  
Yibo Gao ◽  
Yun Zhou ◽  
Benxin Wu
Keyword(s):  
Silicon Carbide ◽  
Laser Ablation ◽  
Electrical Discharge Machining ◽  
High Hardness ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Nanosecond Laser ◽  
Infrared Wavelength ◽  
Nanosecond Laser Ablation ◽  
Mechanical Machining

Silicon carbide, due to its unique properties, has many promising applications in optics, electronics and other areas. However, it is difficult to process using mechanical machining or electrical discharge machining due to its electrical insulation, high hardness and brittleness. Laser ablation can potentially provide a good solution for silicon carbide micromachining. However, the study on silicon carbide ablation by nanosecond laser pulses at infrared wavelength is limited, and will be presented in this paper. The laser ablation rate, laser-induced plasma, the ablated surface morphology and chemical composition change have been studied, and the results are discussed.

Interface-engineered barium magnetoplumbite–wide-bandgap semiconductor integration enabling 5G system-on-wafer solutions for full-duplexing phased arrays

2021 ◽  
Vol 119 (5) ◽  
pp. 051906
Author(s):  
C. Yu ◽  
P. Andalib ◽  
A. Sokolov ◽  
O. Fitchorova ◽  
W. Liang ◽  
...  
Keyword(s):  
Phased Arrays ◽  
Wide Bandgap ◽  
Wide Bandgap Semiconductor

scholarly journals Analytical model for the depth progress of percussion drilling with ultrashort laser pulses

2021 ◽  
Vol 127 (5) ◽  
Author(s):  
Daniel Holder ◽  
Rudolf Weber ◽  
Thomas Graf ◽  
Volkher Onuseit ◽  
David Brinkmeier ◽  
...  
Keyword(s):  
Analytical Model ◽  
Experimental Validation ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Picosecond Pulses ◽  
Hole Depth ◽  
Laser Percussion Drilling ◽  
Pulse Energies ◽  
Ultrashort Laser ◽  
Percussion Drilling

AbstractA simplified analytical model is presented that predicts the depth progress during and the final hole depth obtained by laser percussion drilling in metals with ultrashort laser pulses. The model is based on the assumption that drilled microholes exhibit a conical shape and that the absorbed fluence linearly increases with the depth of the hole. The depth progress is calculated recursively based on the depth changes induced by the successive pulses. The experimental validation confirms the model and its assumptions for percussion drilling in stainless steel with picosecond pulses and different pulse energies.

scholarly journals Thermal laser ablation with tunable lesion size reveals multiple origins of seizure-like convulsions in Caenorhabditis elegans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anthony D. Fouad ◽  
Alice Liu ◽  
Angelica Du ◽  
Priya D. Bhirgoo ◽  
Christopher Fang-Yen
Keyword(s):  
Laser Ablation ◽  
Ventral Nerve Cord ◽  
High Spatial Resolution ◽  
Laser System ◽  
Laser Pulses ◽  
Lesion Size ◽  
Single Neurons ◽  
C Elegans ◽  
Multiple Origins ◽  
Important Means

AbstractLaser microsurgery has long been an important means of assessing the functions of specific cells and tissues. Most laser ablation systems use short, highly focused laser pulses to create plasma-mediated lesions with dimensions on the order of the wavelength of light. While the small size of the lesion enables ablation with high spatial resolution, it also makes it difficult to ablate larger structures. We developed an infrared laser ablation system capable of thermally lesioning tissues with spot sizes tunable by the duration and amplitude of laser pulses. We used our laser system in the roundworm C. elegans to kill single neurons and to sever the dorsal and ventral nerve cords, structures that are difficult to lesion using a plasma-based ablation system. We used these ablations to investigate the source of convulsions in a gain-of-function mutant for the acetylcholine receptor ACR-2. Severing the ventral nerve cord caused convulsions to occur independently anterior and posterior to the lesion, suggesting that convulsions can arise independently from distinct subsets of the motor circuit.

Sign in / Sign up

Export Citation Format

Share Document