magnetic microscope based on second harmonic generation

Near-field imaging though second harmonic generation

One of the objectives of the IMAGeSPIN project is the development of a near-field optical microscope for second harmonic generation (SHG) imaging. In the far field, it is now well established that this non-linear optical technique is an approach that allows the visualization of important magnetic orders for emerging spintronics topics such as antiferromagnetism and teraHertz applications. However, the limitations in spatial resolution of far-field optics restrict the potential of this technique, hence the interest of its extension to the near-field. This tool will thus be an asset for various research axes in spintronics carried out on the Saclay plateau. The main challenge of this part of the IMAGeSPIN project lies in the fact that this technique is not commercialized as such and thus a first part of the project was dedicated to its development (see key dates below). Once this first step has been successfully completed, research is now underway to understand and control multiferroic textures in SHG-SNOM imaging (CEA Saclay/ UMPHy CNRS-Thales collaboration). If successful, the Saclay site will then be equipped with a unique technique that will reinforce the spintronics work of the various groups on the Saclay site.

magnetic microscope based on second harmonic generation
Figure 1: A) neaSPEC SNOM microscope (foreground) and femtosecond laser (background). B) detail of the development of the detection part of the setup. C) laser and SNOM control modules as well as the photon counter, essential for SHG data acquisition. D) Preliminary study of SHG-SNOM on multiferroic textures (CEA Saclay/UMPhys CNRS-Thales collaboration)

Key dates

Spring 2019
August 2019
September 2019

October 2019

end of the call for tenders
Delivery of the optical table
reception and installation of the SNOM (neaSNOM, neaSPEC GmBH)
reception and installation of the femtosecond laser (Fidelity 2, Coherent)

November 2019 – March 2020

handover of the microscope / coupling of the femtosecond laser and the microscope

November 2020 – January 2021

tests of different single photon detectors / purchase of SPPC (Hamamatsu) / reception of photon counter (SR400 Stanford research) / Detection of the 1st SHG photons in near field

January 2021-now

Work to understand and master near-field SHG imaging of ferroelectric and antiferromagnetic textures (CEA SPEC / UMPHy CNRS/Thales collaboration)s 2019