Advancements in Plasmonics: Structures, Optical Properties and Applications

Dear Colleagues,

We are pleased to announce this Special Issue devoted to advancements in plasmonics.

Diffuse interest has been recently devoted to plasmonic nanomaterials, supporting strong light-matter interaction at the subwavelength scale due to excitation of surface plasmon resonances at the metallic (semiconductor)/dielectric interface.

This recently raised a remarkable interest in two-dimensional (2D) systems, where the electronic charge density mainly resides on their surface, whether it comes from a two-dimensional electron gas (2DEG) or Dirac massless carriers living on a graphene monolayer and the surface of a topological insulator. Both cases are intriguingly connected, since surface plasmon polaritons on the two-dimensional interface can be excited by opportunely patterning the active material at the subwavelength scale, thus enabling spectroscopic probing over a broadband infrared spectral range. Alternatively, local excitation of plasmon polaritons in 2D layers can be achieved by exploiting a nanoscale tip in scanning near-field optical microscopy (s-SNOM) that uniquely enables the subwavelength imaging of the plasmonic near-field confined at the 2D/dielectric interface. These techniques thus led to a variety of possibilities for studying optoelectronics properties of novel 2D materials over a broadband infrared and terahertz (THz) frequency range.

More recently, THz spectroscopy gave access to intraband plasmonic excitations, which can even interestingly couple with lattice vibrations via Fano resonance. These low-energy investigations of plasmonic excitations can provide complementary information on the optical properties of the material, for instance by selectively moving within the strong light–matter interactions from the perspective of light to that of the plasmon itself. This can also address non-linear optical phenomena that are severely appearing in Dirac materials, even by addressing the non-linear regime for the plasmonic excitation itself. Indeed, plasmon softening and enhancement of efficient high harmonic generation (HHG) in the THz spectrum have been observed in patterned topological insulator and graphene when excited by intense THz electric field.

Furthermore, localized plasmon resonances can be excited in subwavelength metallic nanostructures, behaving as optical nanoantennas with a strong impact on optical spectroscopies and biosensing, where it is crucial to enhance weak molecular signals.

This Special Issue is dedicated to advancements in plasmonic nanomaterials, their nanofabrication, the experimental and theoretical study of their peculiar optoelectronic properties. These studies are crucial for a deep understanding of the fundamental behavior of novel plasmonic materials and necessary for implementing innovative applications in optoelectronics, nanophotonics, and sensing.

We kindly invite you to contribute your research articles to this Special Issue. Articles based on experimental, numerical, or theoretical results will be considered and evaluated with a rigorous peer-review process.

Dr. Paola Di Pietro
Dr. Maria Giordano
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• Surface plasmon polariton
• 2D materials
• plasmonic nanoantennas
• THz and optical spectroscopies
• sensing
• non-linear spectroscopy