NOVASPEC - Novel instrumentation and applications of IR & THz nano-spectroscopy

The development of novel materials and photonic devices requires ultrahigh-resolution microscopy for mapping local material properties and nanoscale confined light fields. Conventional far-field infrared (IR) and terahertz (THz) microscopy and spectroscopy cannot be applied for this task due to its diffraction limited spatial resolution. Scattering-type near-field optical microscopy (s-SNOM) and nanoscale Fourier transform infrared (nano-FTIR) spectroscopy we pioneered during the past years - can overcome this drawback as they enable IR and THz imaging of material properties and electromagnetic field distributions with nanoscale spatial resolution.

Within this project we want to continue our successful development of s-SNOM and nano-FTIR technologies to further establish this platform for fundamental and applied research in widely different fields, ranging from solid-state physics to bioimaging. In parallel, we want to apply s-SNOM/nano-FTIR for chemical characterization of industrially relevant polymer samples and to explore electromagnetic waves (polaritons) in van der Waals (2D) materials. The project is thus divided into the following three main objectives:

1. Advanced s-SNOM/nano-FTIR instrumentation
We want to continue our successfull development of antenna-based near-field probes, aiming on achieving routinely a spatial resolution in the sub-10 nm range. Particularly, we want to develop efficient probes for the THz spectral range, in which s-SNOM is still much less developed compared to the IR spectral range. To test the THz probes, we will set up a THz near-field microscope. Additionally, we want to add novel functionalities to IR s-SNOM/nano-FTIR. By implementing a liquid cell into one of our s-SNOM setups, we aim on IR nanoimaging in liquid.Further, we want to implement a Raman spectrometer in one of our nano-FTIR setups, in order to enable, for the first time, complementary and correlative IR and Raman nanospectroscopy. Our developments will enable a variety of novel s-SNOM/nano- FTIR applications in widely different fields, ranging from solid-state physics to biochemistry and biology.

2. Application of IR s-SNOM and nano-FTIR for polymer characterization
Existing IR s-SNOM/nano-FTIR setups will be applied for chemical mapping of polymer nanocomposite samples of industrial relevance. By collaborating with technological centers and companies, we aim on establishing a solid basis and protocols for sample preparation, imaging and spectroscopy methodologies, and analysis of the results. We will focus on multicomponent polymer nanoparticles (e.g., which are relevant for coatings, adhesives, cosmetics or drug delivery applications) and polymer membranes (e.g. relevant for gas filtration applications).

3. Exploring polaritons in van der Waals (2D) materials
s-SNOM/nano-FTIR will be applied for studying phonon polaritons in hexagonal boron nitride (h-BN) waveguides and metasurfaces. We aim on fundamental understanding of propagating and localized modes and their field concentration. Based on these studies we want to establish a basis for the development of novel infrared detectors, sensors and spectroscopy tools. We further want to explore polaritons in other vdW materials, including talc and MoO3. In the later, first experiments reveal in-plane anisotropic phonon polariton propagating and record long lifetimes, which could lead to novel directional infrared nanophotonics applications.

This project is funded by RTI2018-094830-B-I00/MCIN/ AEI /10.13039/501100011033/ y por FEDER Una manera de hacer Europa