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Publications

Selected publications

2025 Vmicro white paper Vmicro white paper — HAL

White paper: Introducing Lprobes® and XLprobes® technology for Atomic Force Microscopy

Benjamin Walter, Marc Faucher

We present a new MEMS (MicroElectroMechanical Systems) fabrication process enabling batch production of in-plane Atomic Force Microscopy (AFM) probes with very high lengths and high aspect ratios. This process enables to introduce two probe series: Lprobe® featuring 30 to 40 µm tip lengths, and XLprobe® with tip lengths above 100 µm. These long, high-aspect-ratio probes are fully compatible with standard AFM systems and offer prospects for enhanced imaging range and spatial resolution in topography. We also discuss about benefits that long tips should bring regarding Electrostatic Force Microscopy (EFM), Kelvin Probe Force Microscopy (KPFM), and Piezoresponse Force Microscopy (PFM). Finally, we describe the advantages expected in infrared nanospectroscopy (AFM-IR) and scattering-type Scanning Near-Field Optical Microscopy (s-SNOM).

DOI: 10.5281/zenodo.17463161 View PDF
2026 Nature Communications

High quality-factor terahertz phonon-polaritons in layered lead iodide

Cristiane N. Santos, Flávio H. Feres, Théo Hannotte, Romain Peretti, Mathias Vanwolleghem, Sophie Eliet, Benjamin Walter, Marc Faucher, Adrian Cernescu, Raul O. Freitas, Jean-François Lampin

Layered PbI₂ is shown to support long-lived hyperbolic phonon-polaritons in the deep-terahertz range. Room-temperature s-SNOM measurements reveal strong near-field contrast, low losses and extreme field confinement.

DOI: 10.1038/s41467-026-69027-6 View PDF
2025 2025 50th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)

Advancing THz nanoscopy of 2D materials using compact sources and optimized nanoprobes

Cristiane N. Santos, Pierre Gellie, Adrian Cernescu, Tiago C. Barbosa, Benjamin Walter, Marc Faucher, Benoit Hackens, Ingrid D. Barcelos, Raul O. Freitas, Jean-Francois Lampin

This work demonstrates THz s-SNOM of two-dimensional materials using a compact cryogen-free source. It also examines how probe geometry and length influence near-field performance.

DOI: 10.1109/irmmw-thz61557.2025.11319617
2023 2023 48th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)

Charge carrier profiling with MIR and THz s-SNOM

Cristiane N. Santos, Édouard Lebouvier, Benjamin Walter, Sophie Eliet, N. Chevalier, J. M. Hartmann, Romain Peretti, Marc Faucher, Jean-François Lampin

MIR and THz s-SNOM are used for nanoscale charge-carrier profiling. The study highlights the sensitivity of THz near-field measurements to small variations in semiconductor carrier concentration.

DOI: 10.1109/irmmw-thz57677.2023.10298850
2022 ACS Applied Materials & Interfaces

Imaging of THz Photonic Modes by Scattering Scanning Near-Field Optical Microscopy

Louis Thomas, Théo Hannotte, Cristiane N. Santos, Benjamin Walter, Mélanie Lavancier, Sophie Eliet, Marc Faucher, Jean-François Lampin, Romain Peretti

THz s-SNOM maps the field distribution of photonic micro-resonators. The analysis separates near-field confinement from probe–resonator antenna effects and provides a method for reconstructing the local field.

DOI: 10.1021/acsami.2c01871
2020 2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)

s-SNOM imaging of a THz photonic mode

T. Hannotte, L. Thomas, B. Walter, M. Lavancier, S. Eliet, M. Faucher, J.-F. Lampin, R. Peretti

This conference paper reports s-SNOM imaging of a terahertz photonic mode and discusses the spatial patterns observed when a long AFM probe interacts with a resonant structure.

DOI: 10.1109/irmmw-thz46771.2020.9370928