Alexander Moroz Home Page

Welcome to my home page!

Alexander Moroz

Wave-scattering.com

e-mail: wavescattering@yahoo.com

Personal history:

graduated in 1986, Charles University, Prague, the Czech Republic, with an award from the Ministry of Education of the Czech Republic
Ph.D. in 1991, Institute of Physics, Czech Academy of Sciences, the Czech Republic
September 1991 - March 1992: SNF Fellow at the Institute for Theoretical Physics, ETH Zurich, Switzerland
April 1992 - December 1992: postdoc at the Institute for Theoretical Physics, EPFL Lausanne, Switzerland
January 1993 - September 1993: postdoc at the Institute of Physics CAS, Prague, the Czech Republic
October 1993 - September 1994: postdoc at IPN Orsay, France
October 1994 - August 1996: postdoc at the Theoretical Physics Research Group, University of Birmingham, UK
September 1996 - August 1999: postdoc at the Theory Group of the FOM Institute, AMOLF, Amsterdam, The Netherlands
September 1999 - March 2000: postdoc at the I. Institute of Theoretical Physics, Hamburg University, D-20355 Hamburg, Germany
April 2000-May 2002: postdoc at the Soft Condensed Matter Group, Debye Institute, Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
June 2002-January 2003: Electromagnetics Division, European Space Research and Technology Centre (ESTEC) of the European Space Agency (ESA), PO Box 299, NL-2200 AG Noordwijk, The Netherlands

Hot news!!!
The performance of individual metal nanoparticles (MNPs) is crucially influenced by the localized surface plasmon resonance (LSPR) homogeneous line width or, alternatively, the LSPR dephasing time. So far, two main paths have been pursued in order to improve over the performance of individual spherical metal nanoparticles MNPs: (1) various core-shell MNP morphologies and (2) non-spherical MNP external shapes such as rods, cubes, and prisms. Read here about a third alternative path that has been just published on-line.

Special skills:

You can communicate with me in Czech, Dutch, English, French, German, Polish, Russian, Slovak, and Ukrainian languages.

My free-time research interests

Various subjects of theoretical physics, including general scattering theory, numerical solution of electromagnetic scattering problems, negative refractive index metamaterials, luminescence and scattering properties of small metal nanoparticles, affinity sensors, subwavelength nanoguides, surface plasmons, optical imaging of biotissues, quantum optics, light-matter interactions, theory of optical tweezers, and physics of photonic band-gap structures, or, photonic crystals. My work before 2001 has been summarized in the contribution Towards complete photonic band gap structures below infrared wavelengths to the Proceedings of the NATO ASI Photonic Crystals and Light Localization in the 21st Century (Kluwer, Amsterdam, 2001) and in the contribution K7.5, Photonic Crystals at Near-Infrared and Optical Wavelengths [pdf], in the Proceedings of the MRS Fall Meeting 2001 - BB symposium.
A popular review on the use, properties, and fabrication of photonic crystals has recently appeared in PhysicsWeb. See also Guiding Surface Waves and Tungsten Crystals Could Provide More Power for Electrical Devices. You will find more about why a periodic array of metal rods may be the best way to create narrow, high-frequency microwave signals for everything from satellites to cell phones in Lattice Sends a Crystal Clear Signal. Some additional information, together with selected photonic web links, is supplied below:

[ An early (pre)history of acoustic and photonic crystals | Some photonic crystal headlines, at least 25 years old ... ] [Photonic and computational links | An early history of negative refractive index metamaterials ]

Recent scientific highlights

Previous scientific highlights:

Together with Vassilis Yannopapas we have shown in the article J. Phys.: Condens. Matter. 17, 3717-3734 (2005) that a composite of inherently non-magnetic homogeneous spheres can provide a negative refractive index metamaterial. Note that materials that exhibit magnetic response are:
- i) particularly rare at THz and infrared frequencies and, if they exist,
- ii) they usually suffer from high losses.
The resulting negative refractive index structure is a truly subwavelength structure with wavelength-to-structure ratio as high as 14:1, which appears to be almost by 50% higher than it has been achieved so far using split ring resonators and wires.
Our results were explained in the context of the extended Maxwell - Garnett theory (see accompanying F77 code EFFE2P) and reproduced by the ab initio calculations based on multiple-scattering theory. The role of absorption in the constituent materials is discussed. The centre wavelength lambda of the negative refractive index band can be tuned over a wide frequency range from deep infrared to terahertz (1-10 THz) frequency ranges. This can lead to efficient optical components for terahertz beams, which are required in many scientific and technological applications, ranging from the imaging of biological materials to manipulating quantum states in semiconductors, from drug discovery and medical imaging to security screening.
Power (total and differential) of a dipole radiating anywhere inside or outside a multilayered sphere has been determined. Dipole can be located either outside or embedded anywhere within the multilayered sphere. Among many other quantities, Green's function at coinciding spatial arguments, radiative decay rates, the Ohmic loss contribution to the non-radiative decay rates, and level shifts have been determined. A cumbersome algorithm of H. Chew, P. J. McNulty, and M. Kerker, Raman and fluorescent scattering by molecules embedded in concentric spheres, J. Opt. Soc. Am. 66, 440-444 (1976) is avoided and a new transfer matrix alternative has been provided. The results presented in Annals of Physics (NY) 315, 352-418 (2005) (published online on 7 October 2004, although it was not straightforward to publish it; see story behind this article), where it has since belonged for over one year to the top 5 most downloaded articles, may find various applications for inelastic light-scattering (fluorescence or Raman) spectroscopy for characterizing single micrometer or nanometer sized particles, nano-plasmonics, surface enhanced Raman scattering (SERS), in LIDAR applications for remote sensing of both molecular and particulate constituents of atmosphere, engineering of the radiative decay for biophysical and biomedical applications, imaging of buried saturated fluorescent molecules and imaging of surfaces in near-field optical microscopy, in the study of the effects of light absorption and amplification on the stimulated transition rates of the electric-dipole emission of atoms or molecules embedded in micro- or nano-structured spheres, stimulated Raman scattering, the interplay between lasing and stimulated Raman scattering, etc.
Here you can download a limited Windows executable chew (download also material data file Audat.dat), which calculates the electric dipole radiated power loss together with the dipole power loss due to Ohmic losses for a coated SiO2@X@SiO2 sphere in water. Refractive index of SiO2 is taken to be 1.45, that of water 1.33, and that of X (e.g., gold, silver, etc.) you can supply yourself. The sphere options are identical to that in scattering from a multilayered sphere. You can download full code here.
My second article ``Spectroscopic properties of a two-level atom interacting with a complex spherical nanoshell", Chem. Phys. 117(1), 1-15 (2005) (published online on 9 August 2005) [preprint available as quant-ph/0412094], deals with an application of the theory presented in Annals of Physics (NY) 315, 352-418 (2005) to nano-matryoshka plasmonic spherical structures of Prodan et al. [see Science 302, 419 (2003)]. You can download here accompanying source F77 code CHEWFS and reproduce all the figures in my article. Windows executable is available as an on-line Appendix A of my article.
Any dielectric material can be used to fabricate a photonic crystal with a sizeable and robust complete photonic bandgap (CPBG) in three dimensions, as long as small metal inclusions can be added. These finding (i) open the door for any semiconductor and polymer material to be used as a genuine building block for the creation of photonic crystals with a CPBG and (ii) significantly increase the possibilities for experimentalists to realize a sizeable and robust CPBG at near-infrared and in the visible. See my contribution K7.5, Photonic Crystals at Near-Infrared and Optical Wavelengths [pdf], in the Proceedings of the MRS Fall Meeting 2001 - BB symposium. A more complete version can be found in my article Metallo-dielectric diamond and zinc-blende photonic structures, Phys. Rev. B 66, 115109 (2002) [cond-mat/0209188] [pdf]. In a recent development, purely dielectric diamond structures have been fabricated by F. Garcia-Santamaria et al, Nanorobotic Manipulation of Microspheres for On-Chip Diamond Architectures, Adv. Matter. 14, 1444-1147 (2002).
Exponentially convergent lattice sums of the two-dimensional (2D) free-space periodic (in one dimension) Green function were calculated. These results are discussed in my Opt. Lett. 26, 1119-1121 (2001) [pdf]. Full calculational details, together with the case of a 1D lattice in 3D, have been presented in a follow-up Quasi-periodic Green's functions of the Helmholtz and Laplace equations, J. Phys. A: Math. Gen. 39, 11247-11282 (2006) [erratum] [math-ph/0602021].
The accompanying numerical code OLA is available here and some additional information on that story is supplied here.
For a diamond lattice of dielectric spheres, the bulk photonic KKR method yielded quantitatively different results from earlier plane-wave calculations. See Metallo-dielectric diamond and zinc-blende photonic structures, Phys. Rev. B 66, 115109 (2002) [cond-mat/0209188] [pdf], together with my comment and read an additional information on that story supplied here.
An fcc arrangement of metal spheres can open a full photonic band gap in the visible. Read more in ``Three-dimensional complete photonic bandgap structures in the visible," Phys. Rev. Lett. 83, 5274-5277 (1999).
A critical dielectric contrast for opening a complete photonic band gap in an inverted opal structure has been independently determined by the bulk photonic KKR method. Read more in ``Photonic band gaps of three-dimensional face-centered cubic lattices," J. Phys.: Condens. Matter 11, 997-1008 (1999).
Some peculiar features have been established in a spin-dependent Aharonov-Bohm scattering. Read more in ``The single-particle density of states, phase-shift flip, bound states, and a resonance in the presence of an Aharonov-Bohm potential," Phys. Rev. A 53, 669-694 (1996).