Trace of evanescent wave polarization by atomic vapor spectroscopy

While the behaviour of plasmonic solid thin films in the Kretschmann (also known as Attenuated Total Reflection, ATR) configuration is well-understood, the use of discrete nanoparticle arrays in this optical configuration is not thoroughly explored. It is important to do so, since close packed plasmonic nanoparticle arrays exhibit exceptionally strong light-matter interactions by plasmonic coupling. The present work elucidates the optical properties of plasmonic Au and Ag nanoparticle arrays in both the direct normal incidence and Kretschmann configuration by numerical models, that are validated experimentally. First, hexagonal close packed Au and Ag nanoparticle films/arrays are obtained by air–liquid interfacial assembly. The numerical models for the rigorous solution of the Maxwell’s equations are validated using experimental optical spectra of these films before systematically investigating various parameters. The individual far-field/near-field optical properties, as well as the plasmon relaxation mechanism of the nanoparticles, vary strongly as the packing density of the array increases. In the Kretschmann configuration, the evanescent fields arising from p- and s-polarized (or TM and TE polarized) incidence have different directional components. The local evanescent field intensity and direction depends on the polarization, angle of incidence and the wavelength of incidence. These factors in the Kretschmann configuration give rise to interesting far-field as well as near-field optical properties. Overall, it is shown that plasmonic nanoparticle arrays in the Kretschmann configuration facilitate strong broadband absorptance without transmission losses, and strong near-field enhancement. The results reported herein elucidate the optical properties of self-assembled nanoparticle films, pinpointing the ideal conditions under which the normal and the Kretschmann configuration can be exploited in multiple light-driven applications.

Section: Resultsmentioning

confidence: 99%

Plasmon resonance of gold and silver nanoparticle arrays in the Kretschmann (attenuated total reflectance) vs. direct incidence configuration

Borah

Ninakanti

Bals

et al. 2022

“…To solve this bottleneck and in order to study properties of evanescent fields, some methods are introduced based on nearfield interaction, such as scanning near field optical microscopy (SNOM) 28 , scattering by nano particles or nanostructures 29 , and spectroscopic measurements 30 , 31 . In the case of TSW, the energy would be attenuated by touch of absorbing material, depending on properties of both of evanescent field and absorbing material.…”

Section: Introductionmentioning

confidence: 99%

Vectorial characterization of surface wave via one-dimensional photonic-atomic structure

Salmanpour,

Mosleh,

Hamidi

2023

Self Cite

Quantitative assessment of polarization properties of waves opens up the way for effective exploitation of them in many amazing applications. Tamm surface waves (TSW) that propagate on the interface of periodic dielectric media are proposed for many applications in numerous reports. The polarization state of TSW is not simply intuitive and would not be extracted from reflection spectra. Here considering orientation sensitive nature of the interaction between polarized electromagnetic wave and atom, we try to quantitatively characterize the polarization state of TSWs, excited on the surface of the 1D photonic crystal. To do this we performed direct contact between TSW and rubidium atomic gas by fabrication of a one-dimensional photonic crystal-atomic vapor cell and applied a moderate external magnetic field to create geometrical meaning and a sense of directionality to dark lines in reflection intensity. Our experimental results indicate that transition lines in the reflection spectrum of our hybrid system modify dependent on the orientation of the applied magnetic field and the transverse spin of TSW. We have used these changes to redefine the geometry of Voigt and Faraday for evanescent waves, especially Tamm surface waves. In the end, we performed simple mathematical operations on absorption spectra and extract the ratio of longitudinal and transverse electric field components of the polarization vector of TSW equal to $$\frac{2}{5}$$ 2 5 .

“… 1 – 5 . These studies cover effective control and optimal readout of atoms in micro or nano structures by in decreased volumes by optical near field of miniaturized structures 6 – 8 . Emergence of plasmonics with the possibility of confinement of light in conductive nano structures makes different intended and achievable photonic modes 9 , 10 .…”

Section: Introductionmentioning

confidence: 99%

Multifunctional logic gates based on resonant transmission at atomic-plasmonic structure

Mosleh

Hamidi

Ranjbaran

2022

Self Cite

Regarding the confinement of light at nanoscale dimensions in plasmonic structures, we try to show the impact of hot atomic vapor spectroscopy on a miniaturized scale. In such a combined structure, resonant coupling of the atom to plasmonic mode provides diverse ways to control the optical response of the system. We fabricate an atomic plasmonic cell based on Rubidium atomic vapor and gold plasmonic thin film onto the Kretschmann setup to introduce resonant coupling (EIT-like) of atom-plasmons as a tunable all-optical bandpass filter, switch, or logic gates. These all-optical devices such as NOR and XNOR logic gates are well done based on the filter by incidence angle of light, temperature as well as the external magnetic field. We believe the possibility of easy modulation of atomic susceptibility, not only through direct alteration on atoms but also through common methods available for modulation of plasmonic mode, has the potential to design and fabricate modern all-optical devices.