CW laser machining of hard ceramics—II. Effects of multiple reflections

The article describes the role of polarisation in calculation of multiple reflections. A mathematical model of multiple reflections based on the Stokes vector for beam description and Mueller matrices for description of surface properties is presented. On the basis of this model, the global illumination equation is generalised for the polarisation case and is resolved into volume integration. This allows us to obtain an expression for the Monte Carlo method local estimates and to use them for evaluation of light distribution in the scene with consideration of polarisation. The obtained mathematical model was implemented in the software environment using the example of a scene with its surfaces having both diffuse and regular components of reflection. The results presented in the article show that the calculation difference may reach 30 % when polarisation is taken into consideration as compared to standard modelling.

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3D FEM Simulation to Predict the Heat Affected Zone during Laser Machining on Stainless Steel 304

International Academy of Engineers (IA-E) April 24-25, 2015 Pattaya (Thailand) ◽

10.15242/iae.iae0415201 ◽

2015 ◽

Keyword(s):

Stainless Steel ◽

Heat Affected Zone ◽

Fem Simulation ◽

Laser Machining ◽

3D Fem ◽

Stainless Steel 304

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Basic Study of Two Dimensional Thomson Scattering Measurement System by Multiple Reflections and Time-of-flight of Laser Beam

IEEJ Transactions on Fundamentals and Materials ◽

10.1541/ieejfms.132.574 ◽

2012 ◽

Vol 132 (7) ◽

pp. 574-579

Author(s):

Shingo Ito ◽

Hisashi Sakamoto ◽

Raita Kotani ◽

Michiaki Inomoto ◽

Yasushi Ono ◽

...

Keyword(s):

Laser Beam ◽

Measurement System ◽

Time Of Flight ◽

Thomson Scattering ◽

Two Dimensional ◽

Multiple Reflections ◽

Basic Study ◽

Scattering Measurement

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MODERN POLYMER COMPOSITE MATERIALS AND POSSIBILITIES OF THEIR LASER MACHINING

Alternative Energy and Ecology (ISJAEE) ◽

10.15518/isjaee.2018.10-12.082-104 ◽

2018 ◽

pp. 82-104

Author(s):

S. A. Kotov ◽

N. A. Lyabin ◽

M. А. Kazarian ◽

V. I. Sachkov

Keyword(s):

Composite Materials ◽

Polymer Composite ◽

Polymer Composite Materials ◽

Laser Machining

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Structural and Electrical Characterization of Shaped Beam Laser Recrystallized Polysilicon on Amorphous Substrates

MRS Proceedings ◽

10.1557/proc-4-499 ◽

1981 ◽

Vol 4 ◽

Author(s):

T. J. Stultz ◽

J. F. Gibbons

Keyword(s):

Grain Size ◽

Electrical Characterization ◽

Grain Structure ◽

Electrical Characteristics ◽

Shaped Beam ◽

Beam Laser ◽

Cw Laser ◽

Amorphous Substrates ◽

Circular Beam

ABSTRACTStructural and electrical characterization of laser recrystallized LPCVD silicon films on amorphous substrates using a shaped cw laser beam have been performed. In comparing the results to data obtained using a circular beam, it was found that a significant increase in grain size can be achieved and that the surface morphology of the shaped beam recrystallized material was much smoother. It was also found that whereas circular beam recrystallized material has a random grain structure, shaped beam material is highly oriented with a <100> texture. Finally the electrical characteristics of the recrystallized film were very good when measured in directions parallel to the grain boundaries.

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