Metrological-grade tunable coherent source in the mid-infrared for molecular precision spectroscopy
Authors: Insero G., Clivati C., D’Ambrosio D., Cancio P., Verde M., Schunemann PG., Zondy JJ., Inguscio M., Calonico D., Levi F., De Natale P., Santambrogio G., Borri S.
Autors Affiliation: [Insero, G.; D’Ambrosio, D.; Pastor, P. Cancio; Verde, M.; Inguscio, M.; De Natale, P.; Santambrogio, G.; Borri, S.] CNR, INO, Largo E Fermi 6, I-50125 Florence, FI, Italy and LENS, Via N Carrara 1, I-50019 Sesto Fiorentino, FI, Italy;
[Clivati, C.; D’Ambrosio, D.; Verde, M.; Calonico, D.; Levi, F.; Santambrogio, G.] INRIM Ist Nazl Ric Metrol, I-10135 Turin, Italy; [De Natale, P.; Santambrogio, G.; Borri, S.] Ist Nazl Fis Nucl, Sez Firenze, I-50019 Sesto Fiorentino, FI, Italy; [Schunemann, P. G.] BAE Syst Inc, MER15-1813,POB 868, Nashua, NH 03061 USA; [Zondy, J-J] Nazarbaev Univ, Sch Sci & Technol, Kabanbay Batyr 53, Astana 010000, Kazakhstan
Abstract: We report on a metrological-grade mid-IR source with a 10-14 short-Term instability for high-precision spectroscopy. Our source is based on the combination of a quantum cascade laser and a coherent radiation obtained by difference-frequency generation in an orientation-patterned gallium phosphide (OP-GaP) crystal. The pump and signal lasers are locked to an optical frequency comb referenced to the primary frequency standard via an optical fiber link. We demonstrate the robustness of the apparatus by measuring a vibrational transition around 6 µm on a metastable state of CO molecuels with 11 digits of precision.
Conference title: Conference on Nonlinear Frequency Generation and Conversion – Materials and Devices XVII
More Information: The authors acknowledge financial support from Extreme Light Infrastructure (ELI) European project, from INFN under the SUPREMO project, from Ente Cassa di Risparmio di Firenze under the COSMO project, from EMPIR-15SIB05-OFTEN, which has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme. – The Society of Photo-Optical Instrumentation Engineers (SPIE)KeyWords: Crystal orientation; Frequency standards; Gallium phosphide; III-V semiconductors; Optical fibers; Pumping (laser); Quantum cascade lasers; Spectroscopic analysis, Difference-frequency generation; Frequency metrology; High-resolution spectroscopy; Laser stabilization; Nonlinear crystals, Optical frequency conversion