Concept

Laser-heated pedestal growth

Laser-heated pedestal growth (LHPG) or laser floating zone (LFZ) is a crystal growth technique. A narrow region of a crystal is melted with a powerful CO2 or YAG laser. The laser and hence the floating zone, is moved along the crystal. The molten region melts impure solid at its forward edge and leaves a wake of purer material solidified behind it. This technique for growing crystals from the melt (liquid/solid phase transition) is used in materials research. The main advantages of this technique are the high pulling rates (60 times greater than the conventional Czochralski technique) and the possibility of growing materials with very high melting points. In addition, LHPG is a crucible-free technique, which allows single crystals to be grown with high purity and low stress. The geometric shape of the crystals (the technique can produce small diameters), and the low production cost, make the single-crystal fibers (SCF) produced by LHPG suitable substitutes for bulk crystals in many devices, especially those that use high-melting-point materials. However, single-crystal fibers must have equal or superior optical and structural qualities compared to bulk crystals to substitute for them in technological devices. This can be achieved by carefully controlling the growth conditions. Until 1980, laser-heated crystal growth used only two laser beams focused over the source material. This condition generated a high radial thermal gradient in the molten zone, making the process unstable. Increasing the number of beams to four did not solve the problem, although it improved the growth process. An improvement to the laser-heated crystal growth technique was made by Fejer et al., who incorporated a special optical component known as a reflaxicon, consisting of an inner cone surrounded by a larger coaxial cone section, both with reflecting surfaces. This optical element converts the cylindrical laser beam into a larger diameter hollow cylinder surface. This optical component allows radial distribution of the laser energy over the molten zone, reducing radial thermal gradients.

Official source

https://en.wikipedia.org/wiki/Laser-heated_pedestal_growth

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related lectures (19)

Catalyst Synthesis II: Deposition and Precipitation

Explores catalyst synthesis through deposition and precipitation, covering principles, applications, (co-)precipitation, zeolites, carbon supports, and perovskites.

Structures and Properties of Silicate Materials

Explores the structures and properties of silicate materials, including crystalline formations, ceramics production, and energy of surface tension.

Thin Films: Deposition and Growth

Explores thin film preparation, growth mechanisms, organic film considerations, and deposition techniques in electronics.

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Official source

https://en.wikipedia.org/wiki/Laser-heated_pedestal_growth

About this result

Related lectures (19)

Catalyst Synthesis II: Deposition and Precipitation

Explores catalyst synthesis through deposition and precipitation, covering principles, applications, (co-)precipitation, zeolites, carbon supports, and perovskites.

Structures and Properties of Silicate Materials

Explores the structures and properties of silicate materials, including crystalline formations, ceramics production, and energy of surface tension.

Thin Films: Deposition and Growth

Explores thin film preparation, growth mechanisms, organic film considerations, and deposition techniques in electronics.

Related publications (21)

Programing Crystal Growth with DNA Tile Seeds

Nucleation and crystal growth underpin the formation of ordered structures from disordered systems, yet spontaneous nucleation is inherently stochastic and difficult to control. Seeding can introduce preformed nuclei to guide assembly, which offers a strategy to regulate these processes. Here, we investigate seeded nucleation in the two‐dimensional assembly of trimeric macromolecules using programable DNA tiles as a model system. Introducing a single DNA tile as a nucleation seed enabled size‐ and shape‐con

Wiley2026

Uncovering melt pool dynamics and laser absorption mechanisms in laser powder bed fusion through in-situ experiments and high-fidelity multiphysics simulations

Laser Powder Bed Fusion (LPBF) is a promising metal additive manufacturing (AM) technology that enables high-precision fabrication of high-performance parts with unprecedented design flexibility. However, its widespread adoption remains hindered by the occurrence of various defects, which significantly degrade the mechanical properties and reproducibility of fabricated parts. These defects are inherently linked to the complex and dynamic nature of melt pool behavior, governed by a combination of laser-mater

EPFL2025

Axisymmetric oscillations at L-H transitions in JET: M-mode

Nicola Vianello, Antonio José Pereira de Figueiredo

L to H transition studies at JET have revealed an n = 0, m = 1 magnetic oscillation starting immediately at the L to H transition (called M-mode for brevity). While the magnetic oscillation is present a weak ELM-less H-mode regime is obtained, with a clear ...

IOP Publishing Ltd2017

Related people (14)

Stefano Coda

Teaching & PhD PhD Students Vincent Masson, Luigi Persico, Ewout Koen L. Devlaminck, Martino Bonisolli, Alessandro Balestri, Mackenzie Peter-Fulford Van Rossem, James Winston Irawati Tumbokon, Salomon Guinchard, Inès Vergara, Michele Bottino Past EPFL PhD Students Alessandro Marinoni, Silvano Gnesin, Cornelis Adrianus de Meijere, Josef Kamleitner, Zhouji Huang, Himank Anand, Pedro Andres Molina Cabrera, Dahye Choi, Federico Pesamosca, Aylwin Iantchenko, Jean Arthur Cazabonne

Yong Liu

Arnaud Magrez

Education PhD., Materials Science, summa cum laude, Université de Nantes, 2002 M.S., Chemistry, Université des Sciences et Technologies de Lille, 1999 Academic positions Head of the Crystal Growth Facility, EPFL, 2012-present Research Associate, Laboratoire de Physique de la Matière Complexe, EPFL, 2003-2012 Research Fellow, Peter Grunberg Institute, FZ-Juelich, 2002-2003 Administrative positions at EPFL Scientific staff member, EPFL Assembly, 2015-present Scientific staff member, School Council SB, 2014-present Member of the IPHYS office 2016-present Member of the ICMP office 2012-2015 Member of the safety committee of ICMP 2010-2015

Jean-Marie Drezet

1992-1996: PhD work at Laboratoire de Métallurgie Physique under the supervision of Prof. Michel Rappaz (cf : http://library.epfl.ch/theses/?display=detail&nr=1509) 1997-2000: EMPACT project (European Modelling Programme for Aluminium Casting Technologies) 2001-2004: VIRCAST project (European Virtual Casting) 2005-2006: Study of the sawing process of rolling sheet al. ingots (Alcan Fonds) 2005-2006: WelAIR project (Welding of Airframes, EADS) 2005-2008: study of the electron beam welding of Cu-Cr-Zr alloys (CEA, France) 2006-2008: study of the laser beam welding of Al-Li alloys (EADS, France) 2008-2011: co-supervision with Prof. A. Nussbaumer of the PhD work of C. Acevedo on the influence of residual stresses on the fatigue design of tubular welded joints, http://library.epfl.ch/theses/?nr=5056 2007-2010: co-supervision with Prof. J.-F. Molinari of the PhD work of K. Shahim on the Normal Pressure Hydrocephalus (S. Momjian, HU-Genève et R. Sinkus, ESPCI-Paris), http://library.epfl.ch/theses/?nr=5191 2008-2012: co-supervision with Prof. M. Rappaz of the PhD work of M. Sistaninia on the simulation of solidification cracking using granular models (CCMX-MERU project) 2010-2014: supervision with Prof. M. Rappaz of the PhD work of N. Chobaut on the modelling of stresses during quenching of thick heat treatable aluminium parts (CCMX-MERU project) 2011-2015: supervision with Prof. H. Van Swygenhoven-Moens of the PhD work of P. Schloth on precipitation during quenching of thick heat treatable aluminium parts (CCMX-MERU project)

Anna Fontcuberta i Morral

2014 Associate Professor at the Institut des Matériaux, EPFL 2008 Assistant Professor Tenure Track at the Institut des Matériaux, EPFL 2009 Habilitation in Physics, Technische Universität München 2005-2010 Marie Curie Excellence Grant Team Leader at Walter Schottky Institut, Technische Universität München, on leave from Centre National de la Recherche Scientifique (CNRS, France) 2004-2005 Visiting Scientist at the California Institute of Technology, on leave from CNRS; Senior Scientist and co-founder of Aonex Technologies (a startup company for large area layer transfer of InP and Ge on foreign substrates for the main application of multi-junction solar cells) 2003 Permanent Research Fellow at CNRS, Ecole Polytechnique, France 2001-2002 Postdoctoral Scholar at the California Institute of Technology Study of wafer bonding and hydrogen-induced exfoliation processes for integration of mismatched materials in views of photovoltaic applications Sponsor: Professor Harry A. Atwater 1998-2001 PhD in Materials Science, Ecole Polytechnique Study of polymorphous silicon: growth mechanisms, optical and structural properties. Application to Solar Cells and Thin Film Transistors Advisor: Pere Roca i Cabarrocas 1997-1998 Diplôme dEtudes Approfondis (D.E.A.) in Materials Science at Université Paris XI, France . 1993-1997 BA in Physics at Universitat de Barcelona

Patrick Blanchard

Ambrogio Fasoli

Ambrogio FASOLI was born on November 10, 1964, in Milano, Italy. After a classical high school diploma (Maturità Classica) and graduation from the University of Milano, with the degree of Dottore in Fisica, he obtained his Phd at the Ecole Polytechnique Fédérale (EPFL) with a thesis on chaos in wave-particle interactions in plasmas, which was awarded the Best EPFL Thesis prize, in 1993. He then moved to the JET Joint Undertaking, the largest worlds fusion device, near Oxford, UK, to investigate Alfvén waves and burning plasma physics. In 1995-1996 he took a sabbatical leave, visiting several Universities and Research Institutes in Europe and in the USA, including three months at General Atomics in San Diego. In 1996-1997, during a second period at JET, he participated in the fusion power worlds record experiments in Deuterium-Tritium plasmas at JET. In 1997 he was nominated Assistant Professor in MIT Physics Department, where he led a basic plasma physics group and the international collaboration between MIT and JET. In 2001 Ambrogio FASOLI was nominated Assistant Professor of Physics at EPFL, Lausanne, Switzerland, and Professeur Boursier of the Swiss National Science Foundation. He became member of CRPP Directorate and took the leadership of CRPP basic plasma physics group and of the TCV tokamak, one of the major fusion experiments worldwide. At European level he was scientific coordinator for JET experiments, spokesperson for multi-machine experiments in the frame of International Tokamak Physics Activities, and Project Leader for a JET Enhancement project. In 2005 he became Associate Professor of Physics with tenure at EPFL, then member of EFDA Science and Technology Advisory Committee, and of the Steering Committee of the Association EURATOM-Swiss Confederation. From 2006 he was also Deputy Director, then from 2007 Executive Director of CRPP and from 2008 Full Professor of Physics at EPFL. For a number of years he was the Chair of the EPFL Physics Strategic Committee and a member of the Directorate of the EPFL School of Sciences. Since the summer of 2014 Professor FASOLI was the sole Director of CRPP. He now represents Switzerland in the EUROfusion General Assembly and Bureau, and in the Governing Board for Fusion for Energy. He is member of the EUROfusion DEMO project Board, of the Scientific Board of the Helmotz Virtual Institute on Advanced Microwave Diagnostics, of the European Delegation for the Cooperation between Euratom and the Government of India in Fusion Energy Research, of the European Consortium for the development of the ITER gyratron (EGYC), and participates to numerous international review panels. He chairs the FuseNet Academic Council, the International Advisory Panel for the Laboratory of Excellence Plas@Par in the Sorbonne Universities, the European Consortium for the construction of the ITER microwave Upper Launcher (ECHUL), and the Promotion Committee of the EPFL Faculty of Basic Sciences. He is one the three European representatives in the International Tokamak Physics Activities Coordinating Committee, advising ITER, and the Editor-in-Chief of the IAEA journal Nuclear Fusion. Since January 2019, Ambrogio Fasoli is the Chair of the General Assembly, i.e. the president of EUROfusion, the European Consortium for Development of Fusion Energy. Professor FASOLI is a Fellow of the American Physical Society and since 2001 a Visiting Professor at MIT Physics Department. He is the Director of the Swiss Plasma Center.

Yves Martin

Teaching & PhD Past EPFL PhD Students as codirector Francesco Piras, Jonathan Rossel Courses Fusion and industrial plasma technologies PHYS-632 The course provides an overview of the technologies that are essential for fusion developments and for industrial plasmaapplications, highlighting the synergies between the two fields. The aim is to provide a combined theoretical andexperimental background to the various topics.

Olivier Sauter

Teaching & PhD PhD Students Cassandre Ekta Contré, Antonia Frank, Peizheng Zhang, Jean-Pierre Thomas Svantner, Cristina Venturini, Cosmas Quirin Lorenz Heiss, Daniel Perales Rios, Viacheslav Bochkarev, Jan Jakub Frybes, Paul Véronique Guillaume Devianne Past EPFL PhD Students Clemente Angioni, Petri Nikkola, Alberto Bottino, Andrei Martynov, Emiliano Fable, Costanza Zucca, Federico Felici, Dávid Wágner, Doohyun Kim, Anna Teplukhina, Mengdi Kong, Francesco Carpanese, Simon Van Mulders, Stefano Marchioni, F

Jonathan Graves

Prof. Jonathan P. Graves is a Senior Scientist at EPFL and Honorary Visiting Professor at the University of York, UK. He achieved first class joint honours in Electronic Engineering and Mathematics from the University of Nottingham, UK in 1996. He completed his Ph.D. in Theoretical Mechanics from the University of Nottingham, UK, three years later in 1999. During his Ph.D. he was based in the Culham theory group of the United Kingdom Atomic Energy Authority, developing kinetic descriptions of the internal kink instability, and participating in deuterium-tritium experimental analysis in the Joint European Torus. After a short time in industry, and a postdoc at Nottingham University, he took a position at the Swiss Plasma Center at EPFL, becoming a Senior Scientist in 2014, and became an Honorary Visiting Professor at the University of York, UK, in 2020. In 2015 he became a member of the EUROfusion Scientific and Technical Advisory Committee (STAC) and a member of the EUROfusion DEMO Technical Advisory Group. He is on the editorial board for the journal Plasma Physics and Controlled Fusion, and in 2020 became Scientific Secretary of the Varenna-Lausanne International Workshop in Theory of Fusion Plasmas.

Related concepts (5)

Recrystallization (chemistry)

In chemistry, recrystallization is a technique used to purify chemicals. By dissolving a mixture of a compound and impurities in an appropriate solvent, either the desired compound or impurities can be removed from the solution, leaving the other behind. It is named for the crystals often formed when the compound precipitates out. Alternatively, recrystallization can refer to the natural growth of larger ice crystals at the expense of smaller ones. In chemistry, recrystallization is a procedure for purifying compounds.

Crystal growth

A crystal is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. Crystal growth is a major stage of a crystallization process, and consists of the addition of new atoms, ions, or polymer strings into the characteristic arrangement of the crystalline lattice. The growth typically follows an initial stage of either homogeneous or heterogeneous (surface catalyzed) nucleation, unless a "seed" crystal, purposely added to start the growth, was already present.

Fractional crystallization (chemistry)

In chemistry, fractional crystallization is a method of refining substances based on differences in their solubility. It fractionates via differences in crystallization (forming of crystals). If a mixture of two or more substances in solution are allowed to crystallize, for example by allowing the temperature of the solution to decrease or increase, the precipitate will contain more of the least soluble substance. The proportion of components in the precipitate will depend on their solubility products.