Plasmonic group

Dr. Tomasz Stefaniuk – research assistant professor at the Faculty of Physics UW

Dr. Piotr Wróbel – research assistant professor at the Faculty of Physics UW

Prof. Tomasz Szoplik – full professor at the Faculty of Physics UW

Research:

Plasmonic Group of Tomasz Szoplik is active in simulation, fabrication and characterization of plasmonic nanostructures such as probes for scanning near-field optical microscope (SNOM), single and multilayer metal-dielectric plasmonic lenses, and structured metal films with application in photovoltaics.

Since 2007 the Group has been involved in development of high resolution probes for SNOM. Together with Dr. Tomasz J. Antosiewicz, a former Group member, we proposed the first exact description of SNOM probe radiation that fully corresponds to experimental measurements. Then, we proposed and fabricated aperture, tapered-fiber, metal-coated SNOM probes with corrugated core-metal surface which increases energy throughput. More recently, we proposed and simulated properties of an aperture, tapered-fiber, metal-coated probe which internal azimuthally polarized illumination which concentrates longitudinal component of the magnetic field of light. The probe may serve for measurements of magnetic response of metamaterials.

The Group is equipped with a fabrication tool (e-beam evaporator Lesker PVD75) as well as characterization devices such as scanning SNOM, AFM, STM, and electron microscopes. Functionality of the e-beam evaporator is enhanced with specially designed and built rotating and temperature-controlled sample holders. Performance of the commercial SNOM is improved with additional multiwavelength illumination system designed for transmission mode of work.

Current research of the Plasmonic Group is oriented towards the following topics:

1. Design, fabrication and characterization of plasmonic nanolenses which in the far-field focus visible light to regions with full-width at half-maximum smaller than half a wavelength. The multilayer nanolenses are composed of two layers of metal: the output layer has concentric grooves or slits and the other forms Fabry-Perot resonator giving nearly 80% transmission. The metal films are separated with two dielectric layers: the input one serves as antireflecting coating while the other as metal separator.

2. Design, fabrication and characterization of plasmonic nontransparent metal cathodes for photovoltaics. Passage of a photon through a thin solar cells lasts about one femtosecond. To increase the probability of generation electron-hole pair light should be trapped and density of electric field of light should be enhanced. This is achieved due to plasmonic effects on nanostructured surface of thin polymer solar cells.

3. Studies on morphological, optical and electrical properties of thin metal films. Smoothness of metal surface depends on a wetting interlayer used to control adhesion between metal and substrate particles in the evaporation process. Several wetting layers are tested to choose the ones which prevent island deposition and reduce specific resistivity of films at the same time.

The Group collaborates with Prof. Pierre Chavel, Institut d’Optique Graduate School, Palaiseau, France, in the field of modelling and characterization of micro- and nano-optical devices and systems. Metal-dielectric nanoscale photonic devices support plasmon-polariton surface waves what results in novel functionalities such as superresolution and localized surface plasmon resonances useful in sensors. The second foreign partner is Prof. Concita Sibilia, University of Rome La Sapienza, Italy. Our contacts have been initiated under COST Action P11 and resulted in a book “Photonic Crystals: Physics and Technology”, C. Sibilia, T.M. Benson, M. Marciniak, T. Szoplik, Editors. (Springer, Milano, 2008). At present, Prof. Sibilia shares our interest in asymmetric transmission of terahertz radiation through periodic metal structures.

Research projects:

  1. 2009-13 Research project of the Polish National Center for Research and Development "Superresolving flat lens: design, fabrication, characterisation." Contract N R15 0018 06. Budget: 2,000,000 PLN. (7.09.2009 - 31.03.2013).

  1. 2011-13 Research project of the Polish National Science Center "Subwavelength photonic structures." Contract UMO-2011/01/M/ST3/05734. Budget: 548,600 PLN. (12.12.2011 - 11.06.2013).

  1. 2012-15 Research project of the Polish National Center for Research and Development under Applied Research Program “New polymer solar cells: Influence of polymer structure and cell architecture on efficiency of solar cells based on polyazomethines and polythiophenes.” Contract PBS1/A5/27/2012. Budget 450,000 PLN. (01.12.2012 – 30.11.2015). In collaboration with the Division of Electrotechnology and Materials Science, Electrotechnical Institute (http://www.iel.wroc.pl/); Institute of Physics, PAS; and Faculty of Material Engineering, Technical University of Warsaw.

Selected publications:
  1. P. Wróbel, T. Stefaniuk, T.J. Antosiewicz, A. Libura, G. Nowak, T. Wejrzanowski, M. Andrzejczuk, K.J. Kurzydłowski, K. Jedrzejewski, and T. Szoplik, "Fabrication of corrugated Ge-doped silica fibers," Opt. Express 20, 14508-14513 (2012). http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-20-13-14508

  2. P. Wróbel, T.J. Antosiewicz, T. Stefaniuk, T. Szoplik, "Plasmonic concentrator of magnetic field of light," J. Appl. Phys. 112, 074304 (2012). doi: 10.1063/1.4757033

  3. M. Stolarek, D. Yavorskiy, R. Kotyński, C. Zapata Rodríguez, J. Łusakowski, and T. Szoplik, "Asymmetric transmission of terahertz radiation through a double grating," Opt. Lett. 38, 839-841 (2013).http://www.opticsinfobase.org/ol/abstract.cfm?URI=ol-38-6-839

  4. T. Stefaniuk, P. Wróbel, P. Trautman, T. Szoplik, “Ultrasmooth metal nanolayers for plasmonic applications: surface roughness and specific resistivity,” Applied Optics 53, B237-B241 (2014). http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-53-10-B237

  5. T. Stefaniuk, P. Wróbel, E. Górecka, T. Szoplik, "Optimum temperature for deposition of ultrasmooth silver nanolayers," Nanoscale Research Letters 9, 153-161 (2014).