Non-thermal damage to lead tungstate induced by intense short-wavelength laser radiation (Conference Presentation)

2017 ◽  
Author(s):  
Vojtech Vozda ◽  
Pavel Boháček ◽  
Tomáš Burian ◽  
Jaromir Chalupský ◽  
Vera Hájková ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Short Wavelength ◽  
Thermal Damage ◽  
Lead Tungstate

Photoablation Studies of Polymers, Quartz, and Semiconductors with Vacuum Ultraviolet Laser Radiation

1991 ◽  
Vol 236 ◽  
Author(s):  
Peter R. Herman ◽  
Boyi Chen ◽  
David J. Moore ◽  
Mark Canaga-Retnam
Keyword(s):  
Laser Radiation ◽  
Polymethyl Methacrylate ◽  
Thermal Damage ◽  
Vacuum Ultraviolet ◽  
Medical Industry ◽  
Surface Melting ◽  
Excimer Lasers ◽  
Ultraviolet Laser ◽  
Low Threshold ◽  
Microelectronics Industry

AbstractExcimer lasers sources of 193nm and 157 nm wavelength were used to obtain new photoablation etching rates for several materials of interest to the microelectronics industry. The harder 157nm radiation provided lower ablation rates and smaller threshold fluences for Polyimide and Polymethyl Methacrylate (PMMA) than with 193nm. For normally robust materials like quartz and Teflon (PTFE), the 157nm laser produced clean and smooth ablation sites with low threshold fluences of 620mJ/cm2 and 68mJ/cm2, respectively, features impossible to obtain with conventional excimer lasers at longer wavelengths. The data should help define new micromachining applications of these two materials for the electronic, optical or medical industry. Results are also reported for GaAs and InP based materials which are found to undergo moderate etch rates of 30-80nm/pulse at fluences of ∼3J/cm2, but suffer thermal damage and material segregation due to surface melting.

scholarly journals Optical ionization and heating of gases by intense picosecond KrF laser radiation

1995 ◽  
Vol 13 (1) ◽  
pp. 19-31 ◽  
Author(s):  
A.A. Offenberger ◽  
W. Blyth ◽  
S.G. Preston ◽  
J.S. Wark ◽  
M.H. Key ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Electron Temperature ◽  
Short Wavelength ◽  
Stimulated Raman Scattering ◽  
Multiphoton Ionization ◽  
Thomson Scattering ◽  
Uv Laser ◽  
X Ray ◽  
Above Threshold Ionization ◽  
Inverse Bremsstrahlung Absorption

We report on multiphoton ionization experiments using picosecond (ps) and sub-ps UV-laser radiation at focused intensities up to 1018 W/cm2. The experiments are concerned with determining the electron temperature of optically ionized gases produced by intense KrF lasers. Thomson scattering, stimulated Raman scattering (SRS), and X-ray emission measurements have been made and compared with modeling calculations of heating. A particular objective is to identify the respective roles of above-threshold ionization, nonlinear inverse bremsstrahlung absorption, and SRS in determining the temperature of the electrons. Results for 350-fs pulses are compared with previous measurements for 12-ps pulses (for which strikingly different behavior is observed). The importance of using subps, short-wavelength lasers to minimize electron temperature is confirmed.

Interaction of holmium laser radiation and cortical bone: ablation and thermal damage in a turbid medium

1997 ◽  
Vol 36 (1) ◽  
pp. 32 ◽  
Author(s):  
T. G. Barton ◽  
H.-J. Foth ◽  
M. Christ ◽  
K. Hörmann
Keyword(s):  
Laser Radiation ◽  
Cortical Bone ◽  
Thermal Damage ◽  
Turbid Medium ◽  
Holmium Laser

scholarly journals Retinal thermal damage threshold dependence on exposure duration for the transitional near-infrared laser radiation at 1319 nm

2016 ◽  
Vol 7 (5) ◽  
pp. 2016 ◽  
Author(s):  
Jiarui Wang ◽  
Luguang Jiao ◽  
Xiaomin Jing ◽  
Hongxia Chen ◽  
Xiangjun Hu ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Exposure Duration ◽  
Near Infrared ◽  
Thermal Damage ◽  
Damage Threshold ◽  
Infrared Laser

scholarly journals Увеличение коэффициента полезного действия фотопреобразователей лазерного излучения диапазона 520-540 nm на основе гетероструктур GaInP/GaAs

2021 ◽  
Vol 47 (6) ◽  
pp. 29
Author(s):  
С.А. Минтаиров ◽  
М.В. Нахимович ◽  
Р.А. Салий ◽  
М.З. Шварц ◽  
Н.А. Калюжный
Keyword(s):  
Laser Radiation ◽  
Absorption Edge ◽  
Short Wavelength ◽  
Open Circuit Voltage ◽  
Spectral Response ◽  
Open Circuit ◽  
Simultaneous Increase ◽  
Wavelength Shift ◽  
Total Thickness

Photoconverters (PCs) of laser radiation (LR) for the range 520 - 540 nm based on GaInP/GaAs heterostructures have been investigated. It is shown that a decrease in the CuPt ordering in GaInP layers due to the introduction of antimony atoms leads to a short-wavelength shift of the absorption edge with a simultaneous increase in the open-circuit voltage. An increase in the total thickness of the photoactive layers of PC results in an increase in the spectral response. The performed optimization allows increasing the efficiency of the LR PC from 39.4% to 44.4%.

Corneal thermal damage threshold dependence on the exposure duration for near-infrared laser radiation at 1319 nm

2016 ◽  
Vol 21 (1) ◽  
pp. 015011 ◽  
Author(s):  
Jiarui Wang ◽  
Luguang Jiao ◽  
Hongxia Chen ◽  
Zaifu Yang ◽  
Xiangjun Hu
Keyword(s):  
Laser Radiation ◽  
Exposure Duration ◽  
Near Infrared ◽  
Thermal Damage ◽  
Damage Threshold ◽  
Infrared Laser

THE CHEMISTRY AND BIOLOGY OF GOLD NANOPARTICLE-MEDIATED PHOTOTHERMAL THERAPY: PROMISES AND CHALLENGES

Nano LIFE ◽  
2013 ◽  
Vol 03 (03) ◽  
pp. 1330001 ◽  
Author(s):  
RITA M. CABRAL ◽  
PEDRO V. BAPTISTA
Keyword(s):  
Gold Nanoparticles ◽  
Laser Radiation ◽  
Therapeutic Approach ◽  
Photothermal Therapy ◽  
Thermal Damage ◽  
Laser Light ◽  
Cancer Therapies ◽  
Translation Research ◽  
Localized Heating ◽  
Biological Aspects

Under laser radiation, cells labeled with gold nanoparticles (AuNPs) are believed to suffer thermal damage due to the transfer of the absorbed light from the AuNPs to the cells. This process, which involves complex mechanisms such as the rapid electron–phonon decay in the AuNPs , followed by phonon–phonon relaxation, culminates in the localized heating of both the AuNPs and the cells, setting the rational for the use of these nanostructures, under laser light, in cancer photothermal therapy (PTT). Here, we discuss the chemical and biological aspects of this promising new therapeutic approach, including the advantages over conventional cancer therapies and the challenges that scientists still need to overcome to progress toward translation research.

scholarly journals Mode selection of laser radiation with a wavelength of 980 nm for dissection of upper airway scars. Experimental study

2020 ◽  
Vol 19 (2) ◽  
pp. 38-41
Author(s):  
S. A. Karpishchenko ◽  
◽  
M. Yu. Ulupov ◽  
A. O. Ivantsov ◽  
M. E. Malkova ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Thermal Damage ◽  
Scar Tissue ◽  
Pulse Mode ◽  
Upper Respiratory Tract ◽  
Contact Mode ◽  
Average Width ◽  
Experimental Development ◽  
Continuous Contact ◽  
The Impact

The aim of our work was the experimental development of the optimal laser radiation regime (laser wavelength 980 nm) for dissecting scars of the upper respiratory tract in terms of lateral thermal damage to surrounding tissues. Thermal damage is of fundamental importance when exposed to scar tissue, since it leads to inflammation in the dissection zone, which increases the risk of restenosis. The study was conducted on the basis of the Chair of Otorhinolaryngology with a clinic of Pavlov First Saint Petersburg State Medical University. A pork tendon was chosen as a model of biological tissue due to the similar optical and mechanical properties of scar tissue. The incision was made in the continuous contact mode at a power of 7 W and in the contact pulse mode at a power of 15 W (pulse – 20 ms, pause – 60 ms). The impact on the tissue in these modes was carried out in two directions: from the proximal edge of the tendon to the distal and vice versa. The measurement of the width of the ablation and coagulation zones was carried out under microscopic conditions using an eyepiece micrometer with an increase of ×40. The average width of the zone of lateral tissue damage when exposed in the contact pulse mode in the distal direction is 355±19 nm, which is comparable with the results of a CO2-laser in the superpulse mode.

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