The high quality fundamental and applied scientific research performed at IESL focuses on two main research directions, Laser Interactions & Photonics and Materials & Devices Science & Technology as well as on activities in Astrophysics & Astronomy of smaller size. There is a strong interplay of the research activities within these fields with emphasis on crossing the borders between physics, chemistry, materials science and biology. Training and education through research and the exploitation of technologically mature applications are equally important priorities.
The schematic below illustrates the organizational structure and the facilities of IESL.
Laser Interactions and Photonics
The research activities of the Division cover areas in the fields of atomic and molecular physics, quantum optics, chemical dynamics as well as the study of laser-materials interactions with emphasis on the understanding of the basic mechanisms, the development of methods for the micro- and nano-processing of materials, the development of photonic devices and the application of laser-based diagnostic methods in biology and cultural heritage.
Strong Field Physics
Research is focused on the demonstration, understanding and applications of new phenomena induced during the coherent and/or strong field interaction of ultrashort laser pulses with atomic and molecular systems and the development of novel secondary sources with two directions:
- Physics of generation and characterization of intense XUV attosecond radiation pulses and its exploitation in the study of non-linear phenomena in the XUV spectral region, including XUV-induced-XUV-probe dynamics at the boundary between femto- and atto-second scale
- The development of high average and high peak power ultrashort THz sources using nonlinear interactions and propagation effects of the driving laser pulses with matter. Basic studies focus on the taming of strong ultrashort laser and THz fields, filamentation studies, and strong THz field physics.
Atoms, Molecules and Clusters
This activity focuses on polarization spectroscopy, on chemical dynamics, on the physics and chemistry of atomic clusters as well as on Bose-Einstein condensation and matter waves. More specifically, it focuses on
- The development and application of techniques in polarization spectroscopy to a wide range of problems, including photodissociation dynamics, production and detection of spin-polarized atoms, ultrafast cavity-enhanced ellipsometry for the study of surface dynamics and on cavity enhanced polarimetry.
- The study of chemical dynamics of photodissociation utilizing slice imaging methods, which introduce a temporal spread in the ion cloud along the time-of-flight axis so as to allow the spatial distribution of the particles to be captured using a digital camera.
- The understanding of the formation mechanisms, the stability, the structure and the physicochemical properties of gas-phase clusters as well as their conjugates with biomolecules utilizing a molecular beam apparatus and employing lasers, advanced mass spectrometric and crossed molecular beam scattering in combination with imaging techniques.
- Exploring of the unprecedented potential of matter-wave interferometry and looking at (de)coherence in increasingly complex quantum systems; cold atom systems are explored from single atoms over low density matter waves to very high densities.
Theoretical Atomic Molecular & Optical Physics
The activity studies the interactions between radiation and atoms, quantum linear and non-linear optics, quantum information processing, ultracold atoms, the dynamics of molecular systems and plasma physics. More specifically, the focus is on:
- Theoretical and computational methods to treat real atoms under optical laser pulses of arbitrarily high intensity, ultrashort pulse duration and realistic spatio-temporal shape and, most recently, to study the interaction of atoms with intense, coherent short wavelength radiation (from XUV to hard X-rays), available through the new generation of FEL-based sources.
- Quantum optics and quantum information processing. The former deals with quantum effects associated with the light-matter interaction whereas the latter exploits basic principles of quantum theory, such as superposition and entanglement, thereby extending and generalizing the classical information theory.
- Ultracold atoms and their interaction with radiation as well as the controlled merging of Bose Einstein condensates as well as of Rydberg-blockaded atomic clouds.
- Theoretical and computational chemistry dealing with the dynamics of molecular systems ranging from triatomic molecules with atmospheric interest to large biomolecules, with several thousand degrees of freedom, as well as with modeling and designing nano-materials for energy and environmental applications.
- Development of three-dimensional resistive magnetohydrodynamic codes and numerical studies of confined plasmas.
Photon Science Applications
This covers a broad range of activities on the applications of laser science on biophotonics, guided wave photonics, laser material processing, diagnostic methodologies and instrumentation as well as photonics applications in cultural heritage. More specifically, the activities focus on:
- Biophotonics that includes
- the design, development and application of tomographic technologies for in-vivo imaging in living systems with emphasis on the noninvasive visualization of specific molecular targets and pathways by exploiting the fluorescence signal emitted by fluorescent probes attached to cells or molecules
- the application of non-linear imaging techniques as a powerful tool for elucidating structural and anatomical changes of biological samples and for probing functions and developmental processes in vivo at the microscopic level
- the implementation of laser based micro- and nano-processing methodologies for the engineering of three-dimensional biomaterials or materials that can be utilized as scaffolds for tissue regeneration
- Guided wave photonics dealing with
- the research of materials, light propagation effects, design and fabrication methods for the development of photonic devices mainly in guided wave geometry, with significant effort invested in grating-based and photonic crystal fiber devices
- Laser material processing that includes
- the nonlinear lithography specializing in the fabrication and characterization of micro/nano-structures using two-photon polymerization direct laser writing of photosensitive materials aiming at rapid and flexible fabrication of fully three dimensional structures with sub-100 nm resolution
- the ultrafast laser micro- and nano-processing of materials focusing on the development of novel ultrafast pulsed laser processing schemes for controlled structuring of various materials at micro- and nano-scales
- Laser diagnostic methodologies and instrumentation including
- the development of laser spectroscopic techniques such as laser induced breakdown spectroscopy, laser induced fluorescence and micro-Raman spectroscopy to provide insights about the identity and composition of materials
- the application of time-resolved optical spectroscopy to study the ultrafast processes that occur in condensed matter following excitation by intense, ultrashort laser pulses
- Photonics for Cultural Heritage, which includes
- the development of modern technologies for the study and preservation of Cultural Heritage objects and Monuments and, more specifically, laser-based technologies in the diagnostics and conservation of works of arts and antiquities. These activities revolve around the development and application of laser cleaning methodologies, laser spectroscopic techniques for the compositional characterization of artifacts and holographic metrology techniques and imaging systems for structural diagnostics.
- the laser cleaning of unwanted surface layers of artworks, which is a critical interventive action in Cultural Heritage conservation and aims to enhance the aesthetics and appearance of the artwork, to reveal hidden details or information and eventually to prolong its life and longevity; laser cleaning methodologies enable high control and accuracy, material selectivity and immediate feedback
- the exploitation of the novel analytical, diagnostic and cleaning methodologies in the development of prototype instruments for Cultural Heritage applications
Materials and Devices Division
The research activities of the Materials & Devices Division cover areas in the fields of micron/nano-electronics of compound semiconductors and their devices, nanomaterias and nanophotonics, polymers and soft matter science and technology, biomaterials, electronic, magnetic and photonic materials, hybrid nanostructured materials and metamaterials.
IESL is a member organization of the European research infrastructure ESMI on the investigation of soft matter.
The Group conducts research in the fields of nanoelectronics and nanophotonics, mainly within the European micro/nano-electronics research priority directions of “More than Moore” and “Beyond CMOS”. Its mission is the development of innovative nanostructure materials and fabrication processes leading to new scientific knowledge and know-how on semiconductor material and device technologies. Its research addresses the key enabling technologies (KETs) of nanoelectronics, photonics and advanced materials, the domains of information & communication technologies (ICT) and space, as well as the societal challenges of energy, safety, security, transport and health & wellbeing.
The major current research directions in the microelectronics group are:
- III-Nitride Nano- & Opto-electronics
The activity deals with the molecular beam epitaxy and properties of InN thin films and nano-heterostructures, the epitaxy, properties and device heterostructures of In,Al,Ga,N ternary and quaternary alloys, the heteropitaxy of III-nitrides on novel substrates and the manufacturing of high electron mobility transistors, III-Nitride sensors, MEMs, nanowires, quantum dot memories and devices, polaritonics on free-standing III-nitride membranes and hybrid structures for FRET applications
- III-Arsenide Nano- & Opto-electronics
The activity involves the molecular Beam epitaxy of heterostructures and nanostructures, from complete vertical cavity surface emitting laser diode structures to self-catalyzed nanowires and self- assembled quantum dots in polar directions and the manufacturing of Prototype Polaritonic Devices like room temperature polariton LEDs, manipulation of polariton condensates on a chip, dipolaritons in semiconductor microcavities, of Single-Photon Emitters at elevated temperatures and of Nanowire-based Solar Cells
- Carbon based nanoelectronics
The activity deals with SiC-related materials and devices like high frequency/high power 4H-SiC diodes, avalanche UV photodetectors, high power VJFETs, and nanowire-based field effect transistors, and graphene devices like graphene transistors, mixers, and receivers
- Thin film Optoelectronics
The activity deals with metal oxides and nitrides aiming at transparent and flexible optoelectronic devices (TTFTs, LED, PVs), thermochromics, switches.
- Transparent conductive materials and devices
The research interests of the laboratory focus on the design, the composing and the structural characterization of metal oxides for a wide range of applications like gas sensors, photocatalysis (degradation of inorganic and volatile organic pollutants), transparent thin film transistors, flexible and transparent electronics, electrochromic windows and hydrophilic/hydrophobic materials for self-cleaning surfaces.
This covers a broad range of activities on polymer physics and colloid science and on the synthesis and structural and dynamic properties of functional polymers, biomaterials and hybrid nanostructured materials. More specifically, the activities focus on:
- Polymer and Colloid Science Group
The research activities are directed towards the fundamental understanding of the relationship between microscopic structure - dynamics and macroscopic behavior, the optimization of product properties and processing conditions, and the design of new advanced materials. The activities deal with the dynamics of soft matter (copolymers, rigid polymers, polymer brushes), the rheology of branched, star and ring polymers, the study of colloidal dispersions and the interactions in colloid/polymer dispersions, the properties of photonic and phononic materials based on soft matter systems and the laser writing in polymer solutions.
- Hybrid Nanostructures Group
The activities aim at developing functional material nanostructures, which can be achieved via the specialized design, synthesis and optimization of hybrid materials combining two or more types of functions. The activities focus on the synthesis of functional (co)polymers in bulk and onto surfaces, the design of responsive materials and material surfaces, the structure and dynamics of nano-confined polymers, light-sensitive polymers for nanostructuring and biomedical applications, polymer nano-composites, nanoparticulate catalysts within polymeric nanostructures, the self-assembly of peptides and proteins into fibrils, the controlled positioning of peptide nanostructures in three dimensions and on supports for the directed growth of cells into biomineralized units. The efforts on theory and simulation aim at developing strategies and tools for modelling the behavior of polymers in bulk and near surfaces.
Research is focused on exotic forms of matter incorporating different length scales based on atomic and molecular building blocks. Bulk solid-state compounds, single-crystals or specific nanoscale morphologies, such as hybrid nanocrystals and nanoparticle-assembled solids, are prepared to afford strong electronic correlations (e.g., between spin, charge and lattice). Moreover, research probes quantum magnetism and superconductivity as well as complex electronic phases in reduced dimensions as well as electron motion through materials at their quantum limits.
Theoretical Condensed Matter Physics
A research activity on diluted magnetic semiconductors is mainly focused at the origin of ferromagnetism in these materials where the defect-induced and defect-mediated theory were proposed as a realistic explanation of the newly observed magnetism not only in carbon-based materials but also in diluted magnetic semiconductors, transition metal oxides and related materials. A second activity focuses on the investigation of low dimensional systems such clusters and quantum dots, nanotubes, nanowires and thin films and studies the effect of size confinement together with effects due to the presence of defects, the contacts and/or the vicinity of the system to capacitive elements. The theoretical investigation of these low-dimensional structures studies their structural, electronic, magnetic, optical and transport properties with emphasis in their applications as for example in fabricating new smart materials with multimodal behavior or using them in (nano)devices, catalysis, energy conversion and biological/medical applications
Photonic, Phononic and Metamaterials
The research interest of the group is the development and study (mainly theoretical but also experimental) of artificial composite materials for the control of electromagnetic and elastic waves. The present emphasis is mainly on photonic and phononic crystals, on left-handed or negative index materials, on random lasers and on plasmonic materials. The activity on metamaterials (i.e., negative refractive index materials) for the control of electromagnetic waves emphasizes at the present time optical metamaterials, i.e., metamaterials operating in the optical part of the spectrum, but microwave and IR metamaterials is a subject of considerable attention as well. The activity on photonic and phononic crystals focuses on the existence of band-gaps, modified density of states and surface states, which give rise to various exciting possibilities in what concerns electromagnetic wave emission, reception and propagation control. In addition, the study of the electromagnetic and/or elastic wave propagation in composite materials is used for the understanding of the nature, the structure and the behavior of existing materials of considerable importance (such as soft-matter and biological systems).
The European Commission has chosen Graphene as one of Europe’s first 10-year, one billion euro Future and Emerging Technologies (FET) flagships in order to take graphene and related layered materials from academic laboratories to society. Key applications are, e.g., fast electronic and optical devices, flexible electronics, functional lightweight components and advanced batteries. IESL participates in the FET Flagship via the FORTH’s Graphene Center initiative, coordinated by the Institute of Chemical Engineering Sciences, with scientists from micro/nano-electronics, hybrid nanostructures and laser-materials interaction activities. The activity aims at the production of graphene by CVD or by reduction of graphene oxide using laser beams, the production of graphene oxide and graphene and their functionalization by wet chemistry methods, the use of graphene in organic photovoltaic applications and in graphene/polymer nanocomposites and the utilization of graphene in RF applications focusing mainly on GFET technologies.
Astrophysics & Astronomy
The Astrophysics and Astronomy group studies a broad range of astrophysical phenomena using observational data from ground based and space facilities and by developing new theoretical methods for the interpretation of these observations. The research interests include the astrophysics of compact objects (stellar and supermassive black holes, neutron stars and white dwarfs), properties and evolution of galaxies, and the behavior of matter in the extreme conditions in the vicinity of compact objects. Moreover, the group builds instruments for optical Astronomy and, most importantly, operates and manages the Skinakas Observatory.