Comparison of Holmium:YAG and Thulium Fiber Lasers on the Risk of Laser Fiber Fracture

Objectives: To compare the risk of laser fiber fracture between Ho:YAG laser and Thulium Fiber Laser (TFL) with different laser fiber diameters, laser settings, and fiber bending radii. METHODS: Lengths of 200, 272, and 365 μm single use fibers were used with a 30 W Ho:YAG laser and a 50 W Super Pulsed TFL. Laser fibers of 150 µm length were also tested with the TFL only. Five different increasingly smaller bend radii were tested: 1, 0.9, 0.75, 0.6, and 0.45 cm. A total of 13 different laser settings were tested for the Ho:YAG laser: six fragmentation settings with a short pulse duration, and seven dusting settings with a long pulse duration. A total of 33 different laser settings were tested for the TFL. Three laser settings were common two both lasers: 0.5 J × 12 Hz, 0.8 J × 8 Hz, 2 J × 3 Hz. The laser was activated for 5 min or until fiber fracture. Each measurement was performed ten times. Results: While fiber failures occurred with all fiber diameters with Ho:YAG laser, none were reported with TFL. Identified risk factors of fiber fracture with the Ho:YAG laser were short pulse and high energy for the 365 µm fibers (p = 0.041), but not for the 200 and 272 µm fibers (p = 1 and p = 0.43, respectively). High frequency was not a risk factor of fiber fracture. Fiber diameter also seemed to be a risk factor of fracture. The 200 µm fibers broke more frequently than the 272 and 365 µm ones (p = 0.039). There was a trend for a higher number of fractures with the 365 µm fibers compared to the 272 µm ones, these occurring at a larger bend radius, but this difference was not significant. Conclusion: TFL appears to be a safer laser regarding the risk of fiber fracture than Ho:YAG when used with fibers in a deflected position.

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Comparison of Er:YAG laser, short pulse-duration pulsed dye laser, and long pulse-duration pulsed dye laser in treating sebaceous hyperplasia

Journal of the American Academy of Dermatology ◽

10.1016/j.jaad.2018.05.361 ◽

2018 ◽

Vol 79 (3) ◽

pp. AB82 ◽

Cited By ~ 1

Keyword(s):

Pulse Duration ◽

Er:Yag Laser ◽

Short Pulse ◽

Dye Laser ◽

Pulsed Dye Laser ◽

Short Pulse Duration ◽

Long Pulse

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Temporal integration of partial loudness of helicopter-like sounds

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-2830 ◽

2021 ◽

Vol 263 (2) ◽

pp. 4767-4772

Author(s):

Josef Schlittenlacher ◽

Brian C. J. Moore

Keyword(s):

Pulse Duration ◽

Background Noise ◽

Short Pulse ◽

Temporal Integration ◽

Sound Design ◽

Pulse Trains ◽

Short Pulse Duration ◽

First Results ◽

Fixed Reference ◽

Long Pulse

When developing new vehicles that are to be operated in existing background noise, such as electric vertical take-off and landing aircraft (eVTOLs) in cities, a sound design goal should be to minimize the loudness in the given background noise. Rotorcraft sounds are characterised by their pulses, and the choice of rotor size and number allows to vary the temporal characteristics. We asked participants to compare the loudness of pulse trains with pulse durations of 1, 2, 5, 10 and 20 ms and a pulse rate of 20 Hz in a two-interval, two-alternatives forced choice task and a 1-up/1-down procedure. Street noise was presented simultaneously with the pulse trains, and had the same root-mean-square (RMS) level as the fixed reference pulse train of about 65 dB SPL. First results indicate that the sounds with a short pulse duration need considerably less RMS level to result in the same loudness as a long pulse duration, i.e. the partial loudness of shorter pulses is higher at the same equivalent sound pressure level.

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Temperature Field Simulation of Nitride Hard Film Irradiated by High-Intensity Pulsed Ion Beam

Materials Science Forum ◽

10.4028/www.scientific.net/msf.675-677.521 ◽

2011 ◽

Vol 675-677 ◽

pp. 521-524

Author(s):

Jun Chen ◽

J. Xing ◽

Li Lin ◽

Sheng Zhi Hao ◽

M.K. Lei

Keyword(s):

Pulse Duration ◽

High Intensity ◽

Short Pulse ◽

Ion Beam ◽

Solidification Process ◽

High Energy ◽

High Energy Density ◽

Experimental Result ◽

Nitride Film ◽

Short Pulse Duration

Surface treatment of hard nitride film with high-intensity pulsed ion beam (HIPIB) was investigated in the present research. On considering the high energy density and short pulse duration of HIPIB source, a one-dimension physical model was built according to the structure feature of film-base sample. It was found that the irradiation of HIPIB lead to a very fast thermal recycle of heating rate 1011K/s and cooling rate up to 1010K/s. The highest temperature located at the surface of film irradiated. When using the HIPIB parameters of accelerating voltage 350kV, pulse duration 70ns and current density 60A/cm2, the surface layer of film would be melt with depth of about 0.35mm, that was verified by the experimental result along with the grain refinement effect due to the fast solidification process.

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High-power excilamps with short-pulse duration

10.1117/12.407308 ◽

2000 ◽

Cited By ~ 1

Author(s):

Victor F. Tarasenko

Keyword(s):

Pulse Duration ◽

High Power ◽

Short Pulse ◽

Short Pulse Duration

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Q-switched all-fiber laser with short pulse duration based on tungsten diselenide

Laser Physics ◽

10.1088/1555-6611/aa9e38 ◽

2018 ◽

Vol 28 (5) ◽

pp. 055104 ◽

Cited By ~ 16

Author(s):

Wenyi Li ◽

Yuyi OuYang ◽

Guoli Ma ◽

Mengli Liu ◽

Wenjun Liu

Keyword(s):

Fiber Laser ◽

Pulse Duration ◽

Short Pulse ◽

Tungsten Diselenide ◽

Short Pulse Duration

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Q-Switch Nd:YAG Laser-Assisted Decontamination of Implant Surface

Dentistry Journal ◽

10.3390/dj7040099 ◽

2019 ◽

Vol 7 (4) ◽

pp. 99 ◽

Cited By ~ 2

Author(s):

Namour ◽

El Mobadder ◽

Magnin ◽

Peremans ◽

Verspecht ◽

...

Keyword(s):

Pulse Duration ◽

Nd:Yag Laser ◽

Yttrium Aluminum Garnet ◽

Short Pulse ◽

Sem Analysis ◽

P Value ◽

Implant Surface ◽

Contact Mode ◽

Short Pulse Duration ◽

Clean Contaminated

Peri-implantitis (PI) is an inflammatory disease of peri-implant tissues, it represents the most frequent complication of dental implants. Evidence revealed that microorganisms play the chief role in causing PI. The purpose of our study is to evaluate the cleaning of contaminated dental implant surfaces by means of the Q-switch Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser and an increase in temperature at lased implant surfaces during the cleaning process. Seventy-eight implants (titanium grade 4) were used (Euroteknika, Sallanches, France). Thirty-six sterile implants and forty-two contaminated implants were collected from failed clinical implants for different reasons, independent from the study. Thirty-six contaminated implants were partially irradiated by Q-switch Nd:YAG laser (1064 nm). Six other contaminated implants were used for temperature rise evaluation. All laser irradiations were calibrated by means of a powermetter in order to evaluate the effective delivered energy. The irradiation conditions delivered per pulse on the target were effectively: energy density per pulse of 0.597 J/cm2, pick powers density of 56 mW/cm2, 270 mW per pulse with a spot diameter of 2.4 mm, and with repetition rate of 10 Hz for pulse duration of 6 ns. Irradiation was performed during a total time of 2 s in a non-contact mode at a distance of 0.5 mm from implant surfaces. The parameters were chosen according to the results of a theoretical modeling calculation of the Nd:YAG laser fluency on implant surface. Evaluation of contaminants removal showed that the cleaning of the irradiated implant surfaces was statistically similar to those of sterile implants (p-value ≤ 0.05). SEM analysis confirmed that our parameters did not alter the lased surfaces. The increase in temperature generated at lased implant surfaces during cleaning was below 1 °C. According to our findings, Q-switch Nd:YAG laser with short pulse duration in nanoseconds is able to significantly clean contaminated implant surfaces. Irradiation parameters used in our study can be considered safe for periodontal tissue.

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Point source of UV-radiation with a frequency of 1 khz and short pulse duration

Russian Physics Journal ◽

10.1007/s11182-012-9742-4 ◽

2012 ◽

Vol 54 (11) ◽

pp. 1276-1279 ◽

Cited By ~ 1

Author(s):

E. Kh. Baksht ◽

V. F. Tarasenko ◽

Yu. V. Shut’ko ◽

M. V. Erofeev

Keyword(s):

Point Source ◽

Pulse Duration ◽

Uv Radiation ◽

Short Pulse ◽

Short Pulse Duration

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Forming Fine V-Grooves on a Tungsten Carbide Workpiece with a PCD Electrode by EDM

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.329.631 ◽

2007 ◽

Vol 329 ◽

pp. 631-636 ◽

Cited By ~ 2

Author(s):

Sadao Sano ◽

Kiyoshi Suzuki ◽

Wei Li Pan ◽

Manabu Iwai ◽

Yoshihiko Murakami ◽

...

Keyword(s):

Tungsten Carbide ◽

Pulse Duration ◽

Flat Surface ◽

Short Pulse ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

Chemical Vapor Deposition Diamond ◽

Electrically Conductive ◽

Short Pulse Duration ◽

Low Wear

Polycrystalline diamond (PCD) exhibits a thermal conductivity similar to that of the electrically conductive chemical vapor deposition diamond (EC-CVD diamond) found to function as zero-wear electrodes at short pulse duration. In this study, PCD was used as electrodes applied to EDM on tungsten carbide. Two kinds of PCD (CTB-010 and CTH-025) with a flat surface were used. The wear of the PCD electrodes was about 1.5% for very short pulse duration such as te=1μs, but it was zero wear at te=30μs, though the wear of a Cu-W electrode was 10% even on the machine recommended conditions for the low wear. EDM experiment using a V-shaped PCD electrode with an included angle of 45° was also carried out and the performance was compared with the case using a V-shaped Cu-W electrode. Under the conditions of a no load voltage of 60V, a set peak current of 2A, and a medium pulse duration of te=15μs, there was no wear on PCD electrodes when observed under the SEM, whereas a 50μm-deep wear on the Cu-W electrodes even under the machine recommended condition for the low wear was observed.

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