OptMatLab group featured in the J.A. Woollam 2022 Newsletter
 https://www.jawoollam.com/newsletters/issue-22

The OptMatLab research group studies the properties of matter at the nanoscale by using various spectroscopic techniques. By employing light beams with suitable characteristics, it is possible to obtain detailed information about the microscopic behavior of matter and understand its optical, electronic, chemical and structural properties. The aim of our studies is to create and advance knowledge on innovative materials and devices of relevant scientific and technological interest.

We work on several projects encompassing a wide range of materials, devices and characterization techniques. Over the years, we have built a solid competence in the determination of the optical properties of thin films (oxides, metals, polymers, DNA), bi-dimensional materials (graphene, transition metal dichalcogenides...) and nanoparticles systems. We have a suitable array of instruments that allows us to study the evolution of the materials' properties by varying the ambient conditions, such as temperature and atmosphere. The results of our work are periodically published on international peer-review journals and presesented at seminars and conferences.

The OptMatLab research group is active in the R&D of the multilayer optical coatings, which constitute the main mirrors in the Virgo gravitational wave detector (https://www.virgo-gw.eu/). Within the Einsten Telescope Infrastructure Consortium (ETIC) (https://web.infn.it/einsteintelescope/index.php/it/home-it-it/infrastrutture-e-labs/galileo), OptMatLab is developing systems for thin film deposition and characterization. These films are prototypes for the main mirrors in the Einstein Telescope, a next-generation gravitational wave detector currently under development (https://www.einstein-telescope.it/).

Instrumentation:
- Spectroscopic ellipsometer J.A. Woollam VASE (spectral range: 190-2500 nm)
- Spectroscopic ellipsometer J.A. Woollam M2000 (spectral range: 245-1700 nm)
- Spectroscopic ellipsometer SENTECH SENDIRA (spectral range: 1670-25000 nm – 6000-400 cm-1)
- Confocal Raman microscope Jasco NRS 4100 
- Photothermal Common Path Interferometry (PCI) to measure ultralow optical absorption at 1550 e 1064 nm
- Optical system to measure Photoluminescence

Methods of optical spectroscopy:
- as a function of temperature, from 4 K to 900 K
- ambient atmosphere, high vacuum
- liquid ambient

Systems to grow materials in vacuum:
-   Molecular Beam Epitaxy (MBE)
-   Ion Beam Sputtering with in-situ ellipsometry (J.A. Woollam iSE – 400-1000 nm) 

Shared instrumentation within the Dipartimento di Fisica:
-    Micro-ellipsometer Park EP_4 (lateral resolution: 1 µm, spectral range: 360-1000 nm)
-    X-Ray Photoemission Spectrometer with monochromatized source