Intro
I'm a postdoc doing research and teaching/lecturing. My background
is in electrical and computer engineering, with a specialization
in telecommunications, and an expertise in high-frequency
electromagnetic waves and light-matter interaction. Here's some
profile links: News
- 2023, July: In case you are in Paris for META
2023, I will give a talk (invited) on holographic
metasurfaces and present a poster on graphene-enabled Kerr
microcombs.
- 2023, May: I gave a lecture
at second year ECE students of University of Western
Macedonia, on electromagnetic metasurfaces and their
applications in wireless communications. You can find the
video [here]
and a PDF of my slides [here];
both in Greek! :)
- 2022, September: My paper titled "Ultrafast pulse
propagation in graphene-comprising nanophotonic waveguides
considering nonperturbative electrodynamic nonlinearity"
has been published in JOSAB. [Optica
Publishing Group / DOI] [Full
Text (Preprint) & Supplement]
- 2022, July: Check out my recent talk on "Integrating
Software-Defined Metasurfaces into Wireless Communication
Systems:Design and Prototype Evaluation"
presented at the 27th IEEE Symposium on Computers and
Communications (ISCC 2022). [Video
Recording]
- 2022, July: Our paper titled "Multi-functional
metasurface architecture for amplitude, polarization and
wavefront control" has been published in Physical Review
Applied and got the Editors'
Suggestion! [APS
Journals / DOI] [arXiv] [Supplemental
Material]
- 2022, June: My [GitHub] is finally up
and running :-) I've added four repositories so far: two for
antennas & metasurfaces, one for integrated optics &
waveguides, and one for paraxial ray-optics. I hope more will
come soon.
- 2022, March: First version of my paper, titled "Graphene optical nonlinearity: From the third-order to the non-perturbative electrodynamic regime", is up on [arXiv]. Piecing this together was a long-time effort. Feel free to contact me and discuss!
- 2021, September: My talk at Metamaterials 2021 conference, entitled "Design, Fabrication, and Characterization of a Proof-of-Concept Multi-functional Microwave Metasurface using Static Loads", was presented on the 20th. [IEEE Xplore / DOI]. Contact me for PDF-abstract, Slides or Video.
- 2021, June: My recent talk at CLEO/Europe-EQEC
conference: "Optical Pulse Propagation in
Graphene-comprising Waveguides: Beyond the
Perturbative Nonlinear Regime" [IEEE
Xplore / DOI] [Slides
PDF] [Video
Recording]. Contact me for PDF-abstract.
Research & Interests
My prime field of expertise is electromagnetics, theoretical and computational; specifically guided and radiated waves. My current research is focused in two (distinct) areas: graphene-enhanced nonlinear photonic devices and reconfigurable microwave metasurfaces. Here's a few of my latest published works:
- Ultrafast
pulse propagation in graphene-comprising nanophotonic
waveguides considering nonperturbative electrodynamic
nonlinearity, JOSAB, 2022. [PDF
(preprint)]
- Multifunctional
Metasurface Architecture for Amplitude, Polarization and
Wave-Front Control, PRAppl., 2022. [PDF@arXiv]
- Asymmetric Si-Slot Coupler with Nonreciprocal Response Based on Graphene Saturable Absorption, IEEE JQE, 2021. [PDF@arXiv]
- A Multi-Functional Reconfigurable Metasurface: Electromagnetic Design Accounting for Fabrication Aspects, IEEE TAP, 2020. [PDF@arXiv]
For a full list of my publications, you can always
check my
Google Scholar profile.
My broader interests include silicon photonics, plasmonics, electro-optical phenomena, 2D material physics, metamaterials, liquid crystals, microstructured fibers, classical optics, optical fiber communications, mmWave & THz technology, antennas & propagation. Sounds a lot? Well, a researcher cannot always choose what to work on, and there's always an opportunity to learn new things :)
I have laboratory experience with optical fiber systems,
free-space optics, antenna and RF/microwave technology &
associated measurements.
Brief Resume
I was born in Thessaloniki, in 1982, and got my 5-years MSc
diploma in Electrical and Computer
Engineering (ECE) with a specialization in
Telecommunications in 2005, from the engineering faculty of
the Aristotle University of Thessaloniki (AUTH). I hold another
MSc degree, awarded from ENST/Telecom Paris in
2007, including a 6-month internship at Alcatel-Lucent (now
Nokia Bell Labs) optical transmission group, where I worked on
dispersion managed heterogeneous optical fiber networks.
After my military service at the Hellenic Navy, I resumed research, now focused on integrated photonics, supervised by professor Emmanouil Kriezis (AUTH-ECE Photonics group) leading to a PhD granted in 2014 from ECE/AUTH. My doctorate thesis title is "Analysis, design and characterization of integrated photonic devices based on the hybrid conductor-dielectric-silicon technology" and you can find it here (in Greek, but you can still figure out the math and the figures!).
Since 2014, I've been working as a postdoctoral researcher affiliated with AUTH and FORTH (IESL and ICS), involved in a number of grants, scholarships and research projects, both national and European. The Apart from R&D, I've served as an adjunct lecturer at ECE-AUTH (2016-2018) and also at the School of ECE of the University of Western Macedonia (2016-present), fully in charge of teaching senior year undergraduate courses: photonics, optics and antennas & propagation.
Computational Electromagnetics
Throughout my involvement with research, from 2004 to this
day, I've developed scientific software and simulation tools
primarily in MATLAB. It's something that I enjoy and also find
useful; when both happen in the same project, so much the
better! So, my main tools are various 1D and 2D
full-vector mode-solvers and
beam-propagation methods (BPM), implemented with
analytical formulas (where possible, e.g., when a characteristic
equation can be formulated) or finite difference/element methods
(FDM/FEM), for complicated geometries. It's surprising how many
things one can do with only these tools! Other, minor projects
include coupled spatiotemporal ODEs (e.g. multi-pulse
propagation in nonlinear waveguides coupled with carrier
effects), ray/geometrical optics, and FDTD.
I'm presently setting up my [GitHub] page, to share
these codes, as most of them can be handy tools for engineers in
optics and photonics. Some of them are educational, but can
easily be converted into R&D tools. Here's a list of what
I've developed, with the ones already on GitHub marked in blue. If something from the list below interests
you, don't hesitate to contact me. Maybe we
can collaborate, on development and/or in applications.
Electromagnetics:
- [2D solver] --> Finite-element anisotropic vectorial
eigenmode solver (I call it FEAVES for short), with
post-processing and visualization. This is my main
"workhorse". Supports bulk and sheet (graphene-like)
anisotropic lossy materials. Meant for arbitrary
planar/integrated waveguides and photonic-crystal fibers, but
it can handle any type of waveguide, including RF/microwave
transmission lines. I have developed a lot of post-processing
for the extraction of effective waveguide parameters, e.g.,
GVD and nonlinear parameter "gamma" used in coupled nonlinear
multi-channel/mode pulse propagation (NLSE framework).
- [2.5D solver] --> Finite-element BPM (fed by the
solver), including pre-processing & visualization of
geometry and fields. This is my secondary "workhorse" and is
fully compatible with FEAVES, i.e., it supports arbitrary
(incl. transverse-longitudinal) anisotropy in bulk/3D and
sheet/2D (graphene-like) material properties. This BPM uses a
higher-order Padé-approximation to minimize diffraction error.
It was developed for integrated longitudinal/paraxial
structures such as directional couplers, tapers, Y-junctions,
MZI, MMI, AWG. But, apart from integrated waveguide devices,
it can obviously handle any type of low-reflection propagation
media, e.g., laser beams (Gaussian, vortex) in nonlinear
gases, spot formation etc.
- [2.5D solver] --> Finite-difference BPM, with full-vector, semi-TE/TM and scalar variants. Less developed than my FE-BPM, which is more useful in most cases.
- [1D solvers] --> Slab waveguide solver, for one or arbitrarily many slabs. TE & TM modes. Can handle lossy and/or plasmonic materials too. Based on a "smart solution" of the characteristic equation.
- [1D solvers] --> Arbitrary complex-valued index profiles. TE modes only. Based on FD-modelling of the cross-section.
- [1D solvers] --> Step-index single-core fibers. Vector/hybrid (HE modes) and scalar formulation (LP modes). Supports plasmonic "tubes" (e.g. graphene-clad microfibers in THz). Based on characteristic equation solution.
- [1.5D solver] --> FD-BPM (with feeding from above mentioned 1D solver), including pre-processing & visualization of geometry and fields.
- [Matrix methods] --> Paraxial methods for transmissive (and unfolded-reflective) optical systems w/ multiple apertures and stops. Used for estimation of entrance/exit pupils and all cardinal points.
- [Ray Tracing] --> 2D ray-tracing, both sequential (e.g.
for lens analysis) and arbitrary (e.g., for free-space
optics), with visualization & post-processing, e.g., for
calculation of wavefront shape, F-number etc.. Supports
aspheric (and some free-form) optical surfaces, while
ray-polarization/amplitude tracking (via Fresnel coefficients)
and diffractive surfaces implementation are underway.
- [Ray Tracing] --> 3D sequential ray-tracing for accurate
lens design, with visualization & post-processing (e.g.
spot-diagrams).
- [Aberrations] --> Analytical object-image formation, on a pixel-sensor
- [Scattering] --> Huygens-Fresnel
scattering-pattern approximation (at farfield/Fraunhofer
region) for reflect-arrays and metasurfaces, using physical
optics concepts.
I'm also experienced in several commercial computer-aided
engineering tools (CST, HFSS, COMSOL, FlexPDE), and their
scripting/interfacing with more research-friendly environments
(MATLAB!).
Links
Here's some links relevant to me (profile pages, mostly).
- AUTH-ECE Photonics (Emmanouil Kriezis group)
- my [Google
Scholar]
- my [GitHub]
- my [LinkedIn]
- my [ResearchGate]
- my [ORCID]
- my [Twitter]