Complex refractive indices in the TeraHertz domain of samples from atmospheric aerosol sources

Jeyan Bichon (1, 2) , Melanie Lavancier (2, 3) , Denis Petitprez (4) , Alexandre Deguine (4) , D. Hourlier-Bahloul (5, 3) , Karine Deboudt (6) , Hervé Herbin (7) , Guillaume Ducournau (2, 3) , Romain Peretti (2, 3) , Sophie Eliet (8, 3)

1 UB - Université de Bordeaux
2 PHOTONIQUE THZ - IEMN - Photonique THz - IEMN
3 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
4 PC2A - Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522
5 EPIPHY - IEMN - EPItaxie et PHYsique des hétérostructures - IEMN
6 LPCA - Laboratoire de Physico-Chimie de l'Atmosphère
7 LOA - Laboratoire d’Optique Atmosphérique - UMR 8518
8 PCMP - IEMN - Plateforme de Caractérisation Multi-Physiques - IEMN

We report the TeraHertz (THz) characterization of calcium carbonate (CaCO3) particles, one of the major components of desert dust, to determine the real and imaginary parts of their complex refractive indices. The optical characterization is done by TeraHertz Time Domain Spectroscopy (THz-TDS) technique. CaCO3 powders are diluted with High Density PolyEthylene (PE) at different concentrations (0.1% to 75% of CaCO3) and compressed in pellets. Time-traces are then fitted using the Fit@TDS algorithm developed by Photonic TeraHertz group members, and the complex refractive indices are extracted. We support the optical characterization by a morphological characterization by Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX) analysis after resuspension of particles and filtration on a polycarbonate 0.2 µm pore filter.

Mots clés: aerosols; calcium compounds; crystal morphology; filtration; polymers; powders; refractive index; scanning electron microscopy; terahertz wave spectra; X-ray chemical analysis

Domaines: Physique [physics]; Océan, Atmosphère; Sciences de l'ingénieur [physics]

Jeyan Bichon, Melanie Lavancier, Denis Petitprez, Alexandre Deguine, D. Hourlier-Bahloul, et al.. Complex refractive indices in the TeraHertz domain of samples from atmospheric aerosol sources. 2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz), Aug 2021, Chengdu, China. pp.1163, ⟨10.1109/irmmw-thz50926.2021.9566988⟩. ⟨hal-03403999⟩