Estimation of optimal conditions for laser beam focusing in a turbulent atmosphere from a target image

2016 ◽  
Author(s):  
Vadim V. Dudorov ◽  
Anna S. Eremina
Keyword(s):  
Laser Beam ◽  
Turbulent Atmosphere ◽  
Optimal Conditions ◽  
Target Image ◽  
Beam Focusing

Laser Failure Isolation Techniques Demonstrated On Test Structures

2008 ◽  
Author(s):  
Frank S. Arnold
Keyword(s):  
Integrated Circuits ◽  
Laser Beam ◽  
Case Studies ◽  
Induced Resistance ◽  
Simple Test ◽  
Resistance Change ◽  
Cross Sectional ◽  
Beam Focusing ◽  
Isolation Techniques ◽  
Heating Effects

Abstract To be better prepared to use laser based failure isolation techniques on field failures of complex integrated circuits, simple test structures without any failures can be used to study Optical Beam Induced Resistance Change (OBIRCH) results. In this article, four case studies are presented on the following test structures: metal strap, contact string, VIA string, and comb test structure. Several experiments were done to investigate why an OBIRCH image was seen in certain areas of a VIA string and not in others. One experiment showed the OBRICH variation was not related to the cooling and heating effects of the topology, or laser beam focusing. A 4 point probe resistance measurement and cross-sectional views correlated with the OBIRCH results and proved OBIRCH was able to detect a variation in VIA fabrication.

scholarly journals Effect of Laser Beam Focusing Adjustment on the Processing Quality of Aluminum Nitride Ceramic Micro-Holes

2021 ◽  
Vol 1865 (2) ◽  
pp. 022004
Author(s):  
Chunyan Yang ◽  
Yun Hao ◽  
Yangping Li ◽  
Bozhe Wang ◽  
Hai Yuan ◽  
...  
Keyword(s):  
Aluminum Nitride ◽  
Laser Beam ◽  
Processing Quality ◽  
Beam Focusing ◽  
Micro Holes

Expansion of a Focused Laser Beam in the Turbulent Atmosphere

1971 ◽  
Vol 49 (10) ◽  
pp. 1233-1248 ◽  
Author(s):  
A. D. Varvatsis ◽  
M. I. Sancer
Keyword(s):  
Laser Beam ◽  
Free Space ◽  
Turbulent Atmosphere ◽  
Focal Plane ◽  
Spot Size ◽  
Small Aperture ◽  
Forward Scatter ◽  
Green’S Theorem ◽  
Focused Beams ◽  
Weakly Dependent

This work examines the expansion of a focused laser beam in the turbulent atmosphere. The formulation is based on Green's theorem and the valid assumption that the turbulent atmosphere is a forward-scatter medium for wavelengths of interest (0.6 μ < λ < 11 μ). The main results are: (1) the spot size at the free-space focal plane in the presence of turbulence is independent of the aperture radius, and is only weakly dependent on the wavelength, (2) the focal plane can be significantly shifted for small aperture radii, short wavelengths, and long free-space focal lengths, (3) the effect of the atmosphere is pronounced only close to the free-space focus and very far away, and (4) the turbulent atmosphere has a stronger effect on weakly focused beams rather than strongly focused beams, except very close to the free-space focus, where the effect is more pronounced for strongly focused beams.

Laser beam focusing through the scattering medium by means of adaptive optics

2017 ◽  
Author(s):  
Ilya Galaktionov ◽  
Alexis Kudryashov ◽  
Julia Sheldakova ◽  
Alexander Nikitin
Keyword(s):  
Laser Beam ◽  
Adaptive Optics ◽  
Scattering Medium ◽  
Beam Focusing

scholarly journals Studies on propagation of laser beam array with initial phase distributions in a turbulent atmosphere

2009 ◽  
Vol 58 (7) ◽  
pp. 5098
Author(s):  
Zheng Wei-Wei ◽  
Wang Li-Qin ◽  
Xu Jing-Ping ◽  
Wang Li-Gang
Keyword(s):  
Laser Beam ◽  
Turbulent Atmosphere ◽  
Initial Phase ◽  
Beam Array

Laser beam propagation through the turbulent atmosphere with precipitation

1988 ◽  
Vol 27 (17) ◽  
pp. 3704 ◽  
Author(s):  
A. G. Borovoy ◽  
G. Ya. Patrushev ◽  
A. I. Petrov
Keyword(s):  
Laser Beam ◽  
Turbulent Atmosphere ◽  
Beam Propagation ◽  
Laser Beam Propagation
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