TY  - CONF
AU  - Stojanović, Danka
AU  - Ralević, U.
AU  - Demirhan, Y.
AU  - Aygun, G.
AU  - Ozyuzer, L.
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11824
AB  - Metamaterials that respond resonantly in interaction with the terahertz (THz) electromagnetic waves are significant for the achievement of diverse optical functionalities in THz spectral range [1]. Also, they are virtually desirable platforms for investigating chiral effects which rise due to different interaction of metamaterials with left and right circularly polarized light [2,3]. Light polarization is an important feature of electromagnetic waves and manipulation of polarization plays pivotal role in various areas such as communications, imaging and sensing. One of potential applications of the THz metadevices is for protein quality control in the biotechnology or food industries [4]. Chiral properties of metamaterial can be modified via different external influences, such as by changing the interlayer twist angle, adding a dielectric spacer, or modulating its thickness. Twisting or rotating achiral layered structures in parallel planes enables engineering of the extrinsic chirality and consequential optical performance. For example, the twist angle from counterclockwise rotation of an upper layer with respect to the one under it, leads to a left-handed stacking geometry [5]. In this study, we performed numerical simulations of the metamaterial structure in terahertz frequency range, 0.25-0.75 THz. The numerical simulations were done for the case of two parallel gold rosettes on sapphire substrates in which we analyzed the influence of rotating one rosette with respect to the another on chiral properties. Two geometries of the rosette based structures were studied. First geometry is based on resonator which consists of two same parallel rosettes and the second one of two parallel rosettes, but one of them is trimmed.
PB  - Belgrade : Vinča Institute of Nuclear Sciences
C3  - PHOTONICA2023 : 9th International School and Conference on Photonics : book of abstracts; August 28 - September 1, 2023; Belgrade
T1  - Rosette based metamaterial for circularly polarized terahertz waves manipulation
SP  - 132
EP  - 132
UR  - https://hdl.handle.net/21.15107/rcub_vinar_11824
ER  - 

@conference{
author = "Stojanović, Danka and Ralević, U. and Demirhan, Y. and Aygun, G. and Ozyuzer, L.",
year = "2023",
abstract = "Metamaterials that respond resonantly in interaction with the terahertz (THz) electromagnetic waves are significant for the achievement of diverse optical functionalities in THz spectral range [1]. Also, they are virtually desirable platforms for investigating chiral effects which rise due to different interaction of metamaterials with left and right circularly polarized light [2,3]. Light polarization is an important feature of electromagnetic waves and manipulation of polarization plays pivotal role in various areas such as communications, imaging and sensing. One of potential applications of the THz metadevices is for protein quality control in the biotechnology or food industries [4]. Chiral properties of metamaterial can be modified via different external influences, such as by changing the interlayer twist angle, adding a dielectric spacer, or modulating its thickness. Twisting or rotating achiral layered structures in parallel planes enables engineering of the extrinsic chirality and consequential optical performance. For example, the twist angle from counterclockwise rotation of an upper layer with respect to the one under it, leads to a left-handed stacking geometry [5]. In this study, we performed numerical simulations of the metamaterial structure in terahertz frequency range, 0.25-0.75 THz. The numerical simulations were done for the case of two parallel gold rosettes on sapphire substrates in which we analyzed the influence of rotating one rosette with respect to the another on chiral properties. Two geometries of the rosette based structures were studied. First geometry is based on resonator which consists of two same parallel rosettes and the second one of two parallel rosettes, but one of them is trimmed.",
publisher = "Belgrade : Vinča Institute of Nuclear Sciences",
journal = "PHOTONICA2023 : 9th International School and Conference on Photonics : book of abstracts; August 28 - September 1, 2023; Belgrade",
title = "Rosette based metamaterial for circularly polarized terahertz waves manipulation",
pages = "132-132",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11824"
}

Stojanović, D., Ralević, U., Demirhan, Y., Aygun, G.,& Ozyuzer, L.. (2023). Rosette based metamaterial for circularly polarized terahertz waves manipulation. in PHOTONICA2023 : 9th International School and Conference on Photonics : book of abstracts; August 28 - September 1, 2023; Belgrade
Belgrade : Vinča Institute of Nuclear Sciences., 132-132.
https://hdl.handle.net/21.15107/rcub_vinar_11824

Stojanović D, Ralević U, Demirhan Y, Aygun G, Ozyuzer L. Rosette based metamaterial for circularly polarized terahertz waves manipulation. in PHOTONICA2023 : 9th International School and Conference on Photonics : book of abstracts; August 28 - September 1, 2023; Belgrade. 2023;:132-132.
https://hdl.handle.net/21.15107/rcub_vinar_11824 .

Stojanović, Danka, Ralević, U., Demirhan, Y., Aygun, G., Ozyuzer, L., "Rosette based metamaterial for circularly polarized terahertz waves manipulation" in PHOTONICA2023 : 9th International School and Conference on Photonics : book of abstracts; August 28 - September 1, 2023; Belgrade (2023):132-132,
https://hdl.handle.net/21.15107/rcub_vinar_11824 .

TY  - CONF
AU  - Isić, G.
AU  - Ralević, U.
AU  - Aškrabić, S.
AU  - Laban, B.
AU  - Vodnik, Vesna
AU  - Vasić, Vesna
AU  - Gajić, R.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12539
AB  - Silver nanoparticles (AgNPs) capped with dye molecules and their J-aggregates often have remarkable optical properties that can lead to applications ranging from nanoscale sensing, light harvestering and bio-labelling to advanced composite materials for novel active and nonlinear optical devices. Here we investigate the J-aggregation of a thiacyanine dye (TC) on the surface of citrate capped AgNP nanoasseblies in which the average diameter of individual AgNPs is around 10 nm. Combining Raman mapping, surface-enhanced Raman spectroscopy (SERS) and atomic force microscopy (AFM), we study the influence of TC concentration on its J-aggregation on AgNPs surface. The TC – AgNPs assemblies were deposited onto freshly cleaved highly oriented pyrolytic graphite and mica surfaces. The spectral signature of citrate ions is identified by (i) the O-H band around 220 cm-1, (ii) the C-H band around 2960 cm-1 and (iii) pronounced blinking in the 1000-1800 cm-1 range. In contrast, dye molecules adsorbed on the nanoparticles are recognized by several stable Raman bands between 200 and 1600 cm-1. In situ AFM measurements indicate that the 'hot spots' are formed either on large single nanoparticles (diameter > 100 nm) or within aggregates of small nanoparticles (with diameters in the 10 - 50 nm range). However, only the latter are found to yield a citrate or TC dye SERS signal. Our study indicates that even in highly concentrated dye solutions, some citrate ions remain attached to the nanoparticles.
C3  - 2nd Optical Nanospectroscopy Conference : Conference book
T1  - Study of thiacyanine dye J-aggregates on single silver nanoparticle assemblies by surface enhanced Raman scattering and atomic force microscopy
SP  - 37
EP  - 37
UR  - https://hdl.handle.net/21.15107/rcub_vinar_12539
ER  - 

@conference{
author = "Isić, G. and Ralević, U. and Aškrabić, S. and Laban, B. and Vodnik, Vesna and Vasić, Vesna and Gajić, R.",
year = "2015",
abstract = "Silver nanoparticles (AgNPs) capped with dye molecules and their J-aggregates often have remarkable optical properties that can lead to applications ranging from nanoscale sensing, light harvestering and bio-labelling to advanced composite materials for novel active and nonlinear optical devices. Here we investigate the J-aggregation of a thiacyanine dye (TC) on the surface of citrate capped AgNP nanoasseblies in which the average diameter of individual AgNPs is around 10 nm. Combining Raman mapping, surface-enhanced Raman spectroscopy (SERS) and atomic force microscopy (AFM), we study the influence of TC concentration on its J-aggregation on AgNPs surface. The TC – AgNPs assemblies were deposited onto freshly cleaved highly oriented pyrolytic graphite and mica surfaces. The spectral signature of citrate ions is identified by (i) the O-H band around 220 cm-1, (ii) the C-H band around 2960 cm-1 and (iii) pronounced blinking in the 1000-1800 cm-1 range. In contrast, dye molecules adsorbed on the nanoparticles are recognized by several stable Raman bands between 200 and 1600 cm-1. In situ AFM measurements indicate that the 'hot spots' are formed either on large single nanoparticles (diameter > 100 nm) or within aggregates of small nanoparticles (with diameters in the 10 - 50 nm range). However, only the latter are found to yield a citrate or TC dye SERS signal. Our study indicates that even in highly concentrated dye solutions, some citrate ions remain attached to the nanoparticles.",
journal = "2nd Optical Nanospectroscopy Conference : Conference book",
title = "Study of thiacyanine dye J-aggregates on single silver nanoparticle assemblies by surface enhanced Raman scattering and atomic force microscopy",
pages = "37-37",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12539"
}

Isić, G., Ralević, U., Aškrabić, S., Laban, B., Vodnik, V., Vasić, V.,& Gajić, R.. (2015). Study of thiacyanine dye J-aggregates on single silver nanoparticle assemblies by surface enhanced Raman scattering and atomic force microscopy. in 2nd Optical Nanospectroscopy Conference : Conference book, 37-37.
https://hdl.handle.net/21.15107/rcub_vinar_12539

Isić G, Ralević U, Aškrabić S, Laban B, Vodnik V, Vasić V, Gajić R. Study of thiacyanine dye J-aggregates on single silver nanoparticle assemblies by surface enhanced Raman scattering and atomic force microscopy. in 2nd Optical Nanospectroscopy Conference : Conference book. 2015;:37-37.
https://hdl.handle.net/21.15107/rcub_vinar_12539 .

Isić, G., Ralević, U., Aškrabić, S., Laban, B., Vodnik, Vesna, Vasić, Vesna, Gajić, R., "Study of thiacyanine dye J-aggregates on single silver nanoparticle assemblies by surface enhanced Raman scattering and atomic force microscopy" in 2nd Optical Nanospectroscopy Conference : Conference book (2015):37-37,
https://hdl.handle.net/21.15107/rcub_vinar_12539 .