Nonlinear Behaviour of Optical Coatings Subjected to Intense Laser Irradiation

Absolute measurement of residual absorption in optical coatings is steadily becoming more important in thin film characterization, in particular with respect to high power laser applications. A summary is given on the current ability of the laser induced deflection (LID) technique to serve sensitive photo-thermal absorption measurements combined with reliable absolute calibration based on an electrical heater approach. To account for different measurement requirements, several concepts have been derived to accordingly adapt the original LID concept. Experimental results are presented for prominent UV and deep UV laser wavelengths, covering a variety of factors that critically can influence the absorption properties in optical coatings e.g., deposition process, defects and impurities, intense laser irradiation and surface/interface engineering. The experimental findings demonstrate that by combining high sensitivity with absolute calibration, photo-thermal absorption measurements are able to be a valuable supplement for the characterization of optical thin films and coatings.

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Hot electron and x-ray production from intense laser irradiation of wavelength-scale polystyrene spheres

Physics of Plasmas ◽

10.1063/1.2746024 ◽

2007 ◽

Vol 14 (6) ◽

pp. 062704 ◽

Cited By ~ 21

Author(s):

H. A. Sumeruk ◽

S. Kneip ◽

D. R. Symes ◽

I. V. Churina ◽

A. V. Belolipetski ◽

...

Keyword(s):

Laser Irradiation ◽

Intense Laser ◽

Hot Electron ◽

Polystyrene Spheres ◽

X Ray ◽

Wavelength Scale

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Changes in Spectral Acuity following Laser Irradiation

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/107118138002400147 ◽

1980 ◽

Vol 24 (1) ◽

pp. 162-166

Author(s):

D.O. Robbins ◽

H. Zwick ◽

M. Haenlein

Keyword(s):

Visual Acuity ◽

Laser Irradiation ◽

Threshold Value ◽

Laser Flash ◽

Performance Criteria ◽

Intense Laser ◽

Receptor Function ◽

Normal Color Vision ◽

Cumulative Process

Maximal visual acuity and normal color vision are closely associated with foveal receptor function. When the fovea is destroyed or altered by intense laser irradiation, severe and sometimes permanent losses in visual acuity ensue. In this paper we have shown that the threshold for long-term functional alterations in the fovea is determined not only by the wavelength and corneal exposure power of a laser flash but also by the types of performance criteria used to assess visual functioning. Chromatic acuity provides a much lower threshold for permanent alterations (Krypton — 6 mW; Argon — 3 mW) as opposed to achromatic targets (HeNe — 11 mW). Further, the use of chromatic acuity to assess post-exposure functioning can more accurately delineate the specific cone process most affected by the exposing source. The data from these studies also suggest that some relatively long-term (24 h) cumulative process within the retina is occurring which obviously will affect any threshold value determined.

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Slim: a Personal Computer Based Software for Simulation of Laser Interaction with Materials

MRS Proceedings ◽

10.1557/proc-236-533 ◽

1991 ◽

Vol 236 ◽

Cited By ~ 1

Author(s):

Rajiv K. Singh ◽

John Viatella

Keyword(s):

Laser Irradiation ◽

Personal Computer ◽

Rapid Heating ◽

Pulsed Laser ◽

Laser Pulses ◽

Time Dependent ◽

Intense Laser ◽

Laser Interaction ◽

History Of ◽

Short Laser Pulses

AbstractA user-friendly, personal computer (PC) based routine called SLIM [Simulation of Laser Interaction with Materials] has been developed to understand the non-equilibrium effects of high intensity, short laser pulses on different materials. By employing an accurate implicit finite difference scheme with varying spatial and temporal node dimensions, the time-dependent thermal history of laser-irradiated material can be accurately and quickly determined. This program can take into account the temperature dependent optical and thermal properties of the solid, time dependent laser pulse intensity, and formation and propagation of the melt and/or vaporization interfaces induced by intense laser irradiation. The program can also simulate thermal effects on multilayer structures exposed to pulsed laser irradiation It is expected that this simulation routine will be indispensable to all researchers working in the area of pulsed laser processing of materials, including rapid heating, melting, annealing, laser doping, laser deposition of thin films and laser solidification processing.

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