Skip to main content

Mid Infra-Red near-field control by Adiabatic frequency Generation Enabling 20fs/15nm resolution

Periodic Reporting for period 4 - MIRAGE 20-15 (Mid Infra-Red near-field control by Adiabatic frequency Generation Enabling 20fs/15nm resolution)

Reporting period: 2019-09-01 to 2020-02-29

In the project MIRAGE 20-15 we are aiming at merging extremely high spatial and ultrafast temporal resolution
The goal of MIRAGE 20-15 is to merge the extreme temporal resolution single-cycle mid-IR pulses with the spatial resolution of near field scattering optical microscope (aSNOM) in order to observe and control ultrafast phenomena in a spatio-temporal window of 20fs-15nm at mid-IR. It is of particular importance to material science, chemistry, biology and condensed matter physics since the mid-infrared wavelength regime covers the fundamental vibrational absorption bands of many gaseous molecules and bio-molecules. This will open a gateway to all-optical, non-intrusive and label-free in situ studies of peptide evolution, ultrafast processes in 2D materials and topological insulators, photo-induced surface femtochemistry, and protein folding.
In the past 30 months, the team has managed to achieve most of the proposed objectives for this first part of the project, and we have started already the second phase of the MIRAGE 20-15 project.
The first 10 months period was devoted to renovate the class 100,000 optical laboratory and to equip it with state-of-the-art equipment namely a Ti:Sapphire sub 10 fs ultrashort laser system (Venteon OPCPA), a scattering SNOM system with broadband capabilities at the mid-IR and near-IR (NeaSpec SNOM), Spatial light modulators and more.
During that time, the team that is working on this project has been hired.
During the past 20 months, the team has managed to integrate a scattering near field capability with broadband detection at the mid and near-IR and also developed an adiabatic frequency conversion setup that readily delivers few microjoule energy level mid-IR pulses. In that period we have exploited the experimental apparatus and performed experiments with near-field broadband spectroscopy based on Fourier-Transform Infrared (FTIR) and studied the broadband spectral response of plasmonic nanosctructures. Also, we have already combined the achieved near field capability with our near-IR sub 10fs source and a home built pump-probe apparatus, With this unique system, we have, to the best of our knowledge for the first time, measured spatio-temporally the exciton-polaritons excitation and propagation in WSe2 flakes. Currently we are writing two manuscripts that sum-up these experimental achievements. Furthermore, during the work toward the main goals of MIRAGE 20-15, we have been exploring two related research directions – one that is related to enhancing near-field resolution in microscopy and the other was extending our capability of adiabatic frequency conversion to include also nonlinear time-dependent pulses, which open possibilities such as Second Harmonic generation and depleted Sum- and Difference frequency generation (SFG and DFG).
The results we have reported above are already beyond the state of the art in terms of spatio-temporal resolution and near-field hyperspectral imaging. In the second phase of the project we intend to leverage these advancements and apply them to the mid-IR .
Near-field Ultrafast and broadband Pump-probe of Exciton-Polaritons in WSe2.