High-resolution mid-infrared molecular spectroscopy for precision measurements and tests of fundamental physics. – (Mathieu Manceau / LPCNO / Seminar). – 11/07/2025, 14H

Séminaire LPCNO

Mathieu Manceau, Laboratoire de physique des lasers

Salle de conférence, Bâtiment 3R4

Abstract
High spectral resolution gas-phase molecular spectroscopy in the mid-infrared (MIR)—the so-called molecular fingerprint region (3 to 25 μm)—has far-reaching applications, ranging from astrophysics, remote sensing, and Earth sciences to fundamental physics and metrology. Sub-Doppler spectroscopic techniques in the MIR have so far been limited to only a few relatively simple species.
In this talk, I will present our latest efforts at the Laboratoire de Physique des Lasers to overcome current limitations in MIR frequency metrology. Our goal is to extend frequency metrology methods to an increasing number of species and to enable broadband, sensitive, and ultra-precise spectroscopic studies of molecules relevant to fundamental physics, atmospheric science, and astrophysics.
I will specifically highlight our recent instrumental developments, including ultrastable quantum cascade lasers, advances in MIR photonics, and a new source of cold molecules. I will also discuss our ongoing experiments aimed at testing parity symmetry in chiral molecules, and measuring potential variations in the proton-to-electron mass ratio over time and space.
These latter measurements, which involve comparing absorption and emission spectra from cosmic sources with laboratory data, are currently limited by the existing laboratory measurements..