Speaker: Vlatko Gašparić (Wigner RCP)
Title: Photonic nanojet and its combination with plasmonics for enhancing the Raman spectroscopy
Date: Tuesday, February 18, 2025. 10:00
Place: Building 1, Conference room
Abstract:
Today’s field of chemical and structural characterization is unimaginable without Raman spectroscopy, which is present in many modern scientific, industrial and medical laboratories. The significant need for the enhancement of Raman scattering signal has drawn many innovative methods to emerge. One of those methods rely on a narrow non-resonant beam of light generated by illuminating a microlens, which is called a photonic nanojet (PNJ).
In this seminar talk, after the basic introduction of the main concepts, the current state of the art will be presented from the aspect of the enhancement of Raman spectroscopy by the PNJ [1,2], and the computations of the PNJ and its properties [3,4].
Afterwards, the newest accomplishments will be presented: Firstly, the experimental measurements of a combined surface-enhanced Raman scattering (SERS) and PNJ enhancement, which show the behaviour of the method under different experimental parameters. Secondly, the calculations of the PNJ based on generalized Lorenz-Mie theory (GLMT) and lastly the simulations of an optical device for combined plasmonic and PNJ enhancement of Raman scattering which has been optimized by varying the parameters.
[1] V. Gašparić, S. Taccheo, H. Gebavi, D. Ristić, M. Ivanda; 2020, Journal of Raman spectroscopy, 51, p165-175, "Photonic nanojet mediated Raman enhancement: Vertical Raman mapping and simple ray matrix analysis"
[2] V. Gašparić, D. Ristić, H. Gebavi, M. Ivanda; 2021, Applied surface science, 545, p149036, "Resolution and signal enhancement of Raman mapping by photonic nanojet of a microsphere"
[3] V. Gašparić, D. Ristić, T. G. Mayerhöfer, N. Baran, H. Gebavi, A. Maksimović, M. Ivanda; 2022, Journal of Quantitative Spectroscopy and Radiative Transfer, 282, p108121, "Photonic Nanojet of a Gaussian Beam Illuminated Low Refractive Index Microsphere in Air: a Comprehensive Variation of Parameters"
[4] V. Gašparić, T. G. Mayerhöfer, D. Zopf, D. Ristić, J. Popp, M. Ivanda; 2022, Optics Letters, 47, p2534-2537, "To generate a photonic nanojet outside a high refractive index microsphere illuminated by a Gaussian beam"
