Effect of Optical Fiber Output Surface on Laser Induced Shock Wave and Its Application

Abstract For applying shock waves to precise medical procedures like neurosurgery, a reliable generation of micro shock waves is required. Such sensitive applications make limits on usage of conventional underwater shock wave sources like Extracoporeal Shock Waves ESW [1] or micro explosives [2]. In the present study a Q-switched Ho:YAG laser and an optical fiber are used. Advantages of this method over previous shock wave sources are two order of magnitude reduction in focusing area if compared with ESW and elimination of product gases of micro explosives. Nakahara and Nagayama [3] studied underwater shock waves emanated from surface of an optical fiber by pulse Nd:YAG laser input using shadowgraph technique. Their qualitative study limited to visualization of shock waves at its early stage. The present research aims to clarify quantitatively process of the shock wave generation by direct laser beam irradiation through optical fibers, growth and behavior of generated cavities, and structure of heat induced flow in front of the optical fiber.

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Photoacoustic shock wave emission and cavitation from structured optical fiber tips

Applied Physics Letters ◽

10.1063/1.4939511 ◽

2016 ◽

Vol 108 (2) ◽

pp. 024101 ◽

Cited By ~ 9

Author(s):

M. Mohammadzadeh ◽

S. R. Gonzalez-Avila ◽

Y. C. Wan ◽

X. Wang ◽

H. Zheng ◽

...

Keyword(s):

Shock Wave ◽

Optical Fiber ◽

Wave Emission

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Controlling the optical fiber output beam profile by focused ion beam machining of a phase hologram on fiber tip

Applied Optics ◽

10.1364/ao.54.000890 ◽

2015 ◽

Vol 54 (4) ◽

pp. 890 ◽

Cited By ~ 4

Author(s):

Jiho Han ◽

Martin Sparkes ◽

William O’Neill

Keyword(s):

Optical Fiber ◽

Focused Ion Beam ◽

Ion Beam ◽

Beam Profile ◽

Output Beam ◽

Phase Hologram ◽

Fiber Output

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Test results of optical fiber cable sensitivity to underwater explosion shock wave

10.1117/12.316998 ◽

1998 ◽

Author(s):

Kee P. Koo ◽

Ralph Posey, Jr. ◽

Sandeep T. Vohra ◽

W. D. Gottwald

Keyword(s):

Shock Wave ◽

Optical Fiber ◽

Underwater Explosion ◽

Test Results ◽

Optical Fiber Cable

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A Novel Acoustic Diagnostic Method on Femtosecond Laser Plasma Shock Wave

Materials Science Forum ◽

10.4028/www.scientific.net/msf.861.287 ◽

2016 ◽

Vol 861 ◽

pp. 287-292

Author(s):

Dong Zhong ◽

Zhong Ming Li ◽

Ruo Lin Ruan ◽

Chen Chun

Keyword(s):

Shock Wave ◽

Acoustic Emission ◽

Femtosecond Laser ◽

Optical Fiber ◽

Laser Plasma ◽

Acoustic Emission Signal ◽

Emission Signal ◽

Plasma Shock Wave ◽

Femtosecond Laser Plasma ◽

Plasma Shock

In the paper, the optical fiber F-P acoustic emission sensing probe has been proposed to monitor online space-time progress of femtosecond laser plasma shock wave for the first time, the structure of sensing probe is microstructure with full optical fiber probes without glue, it can measure weak acoustic emission high frequency signal on femtosecond laser plasma shock wave. In the process of femtosecond laser ablating copper, iron and aluminum, we research and analyze the plasma shock wave acoustic emission signal change regulation under different laser pulse energy and different distance between the laser and the optical fiber sensing probe, and we analyze the feature of the acoustic emission signal spectrum. Experiment establishes a kind of new optical fiber sensing measurement method for femtosecond laser plasma shock wave acoustic emission signal.

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Wavelength Dependence of the Polarization Singularities in a Two-Mode Optical Fiber

International Journal of Optics ◽

10.1155/2012/358093 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7

Author(s):

V. V. G. Krishna Inavalli ◽

Vijay Pottapinjara ◽

Nirmal K. Viswanathan

Keyword(s):

Optical Fiber ◽

Edge Dislocation ◽

Wavelength Dependence ◽

Experimental Demonstration ◽

Input Beam ◽

Left Handed ◽

Linearly Polarized ◽

Intermodal Dispersion ◽

Fiber Output ◽

Elliptically Polarized

We present here an experimental demonstration of the wavelength dependence of the polarization singularities due to linear combination of the vector modes excited directly in a two-mode optical fiber. The coherent superposition of the vector modes excited by linearly polarized Gaussian beam as offset skew rays propagated in a helical path inside the fiber results in the generation of phase singular beams with edge dislocation in the fiber output. The polarization character of these beams is found to change dramatically with wavelength—from left-handed elliptically polarized edge dislocation to right-handed elliptically polarized edge-dislocation through disclinations. The measured behaviour is understood as being due to intermodal dispersion of the polarization corrections to the propagating vector modes, as the wavelength of the input beam is scanned.

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