Optically Pumped Terahertz Molecular Laser: Gain Factor and Validation up to 5.5 THz

Abstract

Quantum cascade laser-pumped terahertz (THz) gas lasers are at the edge of revolutionizing THz science where powerful yet tunable sources have long been lacking. Maybe one of the last remaining drawbacks to a wider use of these instruments lies in the lack of available databases of potentially lasing transitions for users. A new figure of merit, the molecular gain factor is proposed, that allows to discriminate transitions by their lasing potential. Using this factor, catalogs of THz laser lines of ammonia, both ¹⁴NH₃ and ¹⁵NH₃, up to 10 THz are reported. Demonstration of the use of these two catalogs, and of the pertinence of the molecular gain factor, is made by experimentally observing 32 laser lines of ¹⁴NH₃ and 5 lines of ¹⁵NH₃ up to 5.5 THz. Prospects to generalize the use of this molecular gain factor to a wide range of molecules are discussed.

Zachary Buchanan

Chateaubriand Fellow

Zachary was a Chateaubriand Fellow at ISMO in 2019.

Olivier Pirali

Director of Research

My research interests includes high resolution molecular spectroscopy, laboratory astrophysics, and THz generation.

Marie-Aline Martin-Drumel

Researcher

My research interests focus on molecular spectroscopy of stable molecules and reactive species, and its applications for astrophysics and physical-chemistry.