Continuous-wave difference frequency generation in the mid-infrared with orientation-patterned gallium phosphide (OP-GaP) crystals
Authors: Insero G., Clivati C., D\’Ambrosio D., De Natale P., Santambrogio G., Schunemann P.G., Zondy J.-J., Borri S.
Autors Affiliation: Istituto Nazionale di Ottica, INO-CNR, European Laboratory for Nonlinear Spectroscopy, LENS, Via N. Carrara 1, Sesto Fiorentino, 50019, Italy; Istituto Nazionale di Ricerca Metrologica, INRIM, Strada delle Cacce 91, Torino, 10135, Italy; BAE Systems, Inc., MER15-1813, P.O. Box 868, Nashua, NH 03061-0868, United States; Nazarbaev University, School of Science and Technology, Physics Department, Kabanbay Batyr 53, Astana, 010000, Kazakhstan
Abstract: Orientation-patterned gallium phosphide (OP-GaP) crystals are used here for the first time for the generation of continuous-wave coherent mid-infrared radiation around 5.85 µm by difference frequency generation (DFG) of a Nd:YAG laser at 1064 nm and a diode-laser at 1301 nm. We provide the first characterization of the linear, thermo-optic and nonlinear properties of OP-GaP in a DFG configuration, and we derive an effective nonlinear coefficient deff = 17 pm/V (3) for first-order quasi-phase-matched OP-GaP. This novel nonlinear material can be used to referenced the mid-IR light to a frequency standard by locking the pump and signal laser to a near-IR optical frequency comb.
More Information: This work was partially funded by ELI European project, Istituto Nazionale di Fisica Nucleare (INFN) through the SUPREMO project and Horizon 2020 program (EMPIR-15SIB05-OFTEN).KeyWords: Characterization; Crystal orientation; Frequency standards; Gallium alloys; Gallium phosphide; Infrared devices; Infrared radiation; Light sources; Locks (fasteners); Neodymium lasers; Optical frequency conversion; Phase matching; Pumping (laser); Semiconducting gallium, Difference-frequency generation; Frequency metrology; Laser stabilization; Mid-infrared sources; Nonlinear materials, Nonlinear optics