Erbium: yttrium–aluminum–garnet laser induced vapor bubbles as a function of the quartz fiber tip geometry

Mrochen, Michael; Riedel, Peter; Donitzky, Christof; Seiler, Theo

doi:10.1117/1.1381052

Cited by 13 publications

(11 citation statements)

References 21 publications

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“…16 Using shadow photography, we show that the shape of the bubble and its dynamics depend on the FT geometry. In the case of the flat FT, a channel-like bubble is induced, 3,9,21,22,32 while our measurements show that a spherical bubble is developed when erbium radiation is delivered through the conical FT. Thus, we compare the measurements obtained using the conical FT with the Rayleigh model 33 in dimensionless form to analyze the influence of the pulse duration on the bubble's dynamics.…”

Section: Introductionmentioning

confidence: 88%

“…For this reason, the light gathers at the bottom part of the conical FT and exits the FT at different angles defined by Snell's law. 9,42 Therefore, the power density at the exit of the conical FT is increased in comparison with the flat FT.…”

Section: Conical Fiber Tipmentioning

confidence: 98%

“…During each reflection, the portion of reflected light is defined by the Fresnel laws. 9 In our case, the first incidence angle α 0 exceeds 67.6 deg, while the angle of the total internal reflection for the silicawater interface equals α totSW ¼ 63.7 deg, using the refractive index of water n w ¼ 1.274 at λ ¼ 2.94 μm.…”

Section: Conical Fiber Tipmentioning

confidence: 99%

“…[1][2][3][4][5] Of all the infrared lasers, the erbium: yttrium aluminum garnet (Er:YAG) laser, emitting pulsed light at 2.94 μm, has the highest absorption in water. 6 Thus, its radiation delivered through a smalldiameter fiber tip (FT) can be used for a wide range of laser-assisted medical applications, such as lithotripsy, 7 ophthalmology, 8,9 and dentistry. [10][11][12][13][14][15][16][17] Due to the strong absorption of erbium radiation in water, a vapor bubble is formed during the erbium-pulse delivery through an optical fiber that is not in contact with any tissue.…”

Section: Introductionmentioning

confidence: 99%

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Optodynamic energy-conversion efficiency during an Er:YAG-laser-pulse delivery into a liquid through different fiber-tip geometries

2012

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Abstract. When an erbium-laser pulse is directed into water through a small-diameter fiber tip (FT), the absorption of the laser energy superheats the water and its boiling induces a vapor bubble. We present the influence of different FT geometries and pulse parameters on the vapor-bubble dynamics. In our investigation, we use a free-running erbium: yttrium aluminum garnet (Er:YAG) (λ ¼ 2.94 μm) laser that was designed for laser dentistry. Its pulse is directed into the water through FTs with a flat and conical geometry. Our results show that in the case of the conical FT, a spherical bubble is induced, while a channel-like bubble develops for the flat FT. The ratio between the mechanical energy of the liquid medium and the pulse energy, which we call the optodynamic energy-conversion efficiency, is examined using shadow photography. The results indicate that this efficiency is significantly larger when a conical FT is used and it increases with increasing pulse energy and decreasing pulse duration. The spherical bubbles are compared with the Rayleigh model in order to present the influence of the pulse duration on the dynamics of the bubble's expansion.

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Section: Introductionmentioning

confidence: 88%

Section: Conical Fiber Tipmentioning

confidence: 98%

Section: Conical Fiber Tipmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optodynamic energy-conversion efficiency during an Er:YAG-laser-pulse delivery into a liquid through different fiber-tip geometries

2012

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“…Although increased absorption limits the use of long low-OH silica fibers beyond wavelengths of approximately 2.5 mm, previous studies have demonstrated that short low-OH silica fiber lengths, on the order of a few centimeters, are capable of transmitting sufficient Er:YAG laser energy for soft tissue ablation [5,6,8,15]. We demonstrate in this study that long hybrid fibers are capable of being assembled with a simple process that reduces many of the limitations associated with current mid-IR optical fibers, and that sufficient Er:YAG laser energy can be transmitted through these fibers during insertion into a flexible endoscope for potential use in multiple soft and hard tissue laser ablation applications.…”

Section: Introductionmentioning

confidence: 99%

Hybrid germanium/silica optical fibers for endoscopic delivery of erbium:YAG laser radiation

2004

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Shaping photomechanical effects in tissue ablation using 355 nm laser pulses

Herzog

Steinberg

Ishaaya

2016

Journal of Biophotonics

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We investigate the influence of the cladding diameter of an optical delivery fiber on the ablation dynamics of porcine aorta immersed in tetracycline antibiotic solution using 355 nm nanosecond pulses. We manipulate the pressure transients by enforcing a rear rigid interface (applied by an enlargement of the cladding diameter) to the ablated area, which leads to enhanced ablation efficiency along with a reduction in tissue disruption effects. Numerical simulations, based on the finite elements method, are used to study the propagation of the pressure transients within the suggested scheme. Ultrasonic transducers are used for measuring the increased pressure in front of the fiber's facet and the reduced pressure at the fiber's circumference in the presence of large diameter cladding. The increase and decrease are both found to be by a factor of ˜1.8. The width of the cavitation bubble is measured by high-speed photography. An enlargement of 13.8% is demonstrated, at the expense of backward expansion along the fiber's axis. A histopathological in vitro study demonstrates an average enhancement of 12.27% in the diameter of the ablated crater, as well as significant reduction in the disruption effects. Our study sheds light on the potential to improve the ablation efficiency without additional energy cost, along with attaining improved safety for interventional medical procedures.

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Erbium: yttrium–aluminum–garnet laser induced vapor bubbles as a function of the quartz fiber tip geometry

Abstract: The good possibility of controlling the shape and size of vapor bubbles offers a wider range of new applications, especially in ophthalmic microsurgery such as erbium YAG laser vitrectomy.

Cited by 13 publications

References 21 publications

Optodynamic energy-conversion efficiency during an Er:YAG-laser-pulse delivery into a liquid through different fiber-tip geometries

Optodynamic energy-conversion efficiency during an Er:YAG-laser-pulse delivery into a liquid through different fiber-tip geometries

Hybrid germanium/silica optical fibers for endoscopic delivery of erbium:YAG laser radiation

Shaping photomechanical effects in tissue ablation using 355 nm laser pulses

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