Determination of non-linear refractive index of laser crystals and ceramics via different optical techniques

Anno: 2020

Autori: Lamaignere L.; Toci G.; Patrizi B.; Vannini M.; Pirri A.; Fanetti S.; Bini R.; Mennerat G.; Melninkaitis A.; Lukas L.; Hein J.

Affiliazione autori: CEA-CESTA, F33116 Le Barp, France; National Institute of Optics, National Research Council, INO-CNR, Via Madonna Del Piano, Sesto Fiorentino (Florence), 10 50019, Italy; European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara 1, Sesto Fiorentino (Florence), 50019, Italy; Institute of Applied Physics “”N. Carrara””, National Research Council, IFAC-CNR Via Madonna Del Piano 10 50019 Sesto Fiorentino (Florence), Italy; Institute of Chemistry of the Organometallic Compounds, National Research Council, ICCOM-CNR, Via Madonna Del Piano 10, Sesto Fiorentino (Florence), 50019, Italy; Department of Chemistry “”Ugo Schiff””, University of Florence, Via Della Lastruccia, Sesto Fiorentino, (Florence), 3,50019, Italy; CEA, Iramis, SPAM, Saclay, France; Laser Research Center, Vilnius University, Sauletekio ave. 10, LT, Vilnius, 10223, Lithuania; Institute of Optics and Quantum Electronics, Friedrich-Schiller-University Jena and Helmholtz Institute, Jena, Germany.

Abstract: The exact knowledge of optical material parameters is crucial for laser systems design. Therefore, the work reported herein was dedicated to the determination of an important parameter that is typically not known or only known with insufficient precision: the Kerr coefficient determined by the third order non-linearity, also called the n2-parameter. The optical Kerr effect is responsible for the accumulated nonlinear phase (the B-integral) in high energy laser amplifiers, which often represents a serious limitation. Therefore, the knowledge of n2 is especially required for new types of laser materials. In this paper we report measurements carried out on the widely used optical material Ytterbium-doped Yttrium Aluminium Garnet (Yb:YAG) ceramics. Furthermore, the new Neodymium-doped Calcium Fluoride (Nd:CaF2) crystal was investigated. Specifically, three different approaches have been employed to determine experimentally the nonlinear refractive index of these materials. Thus classical Z-scan technique (at two different wavelengths), the degenerated four waves mixing and the time-resolved digital holography techniques, were compared. These different approaches have permitted the precise measurements of these parameters as well as their dispersion estimations.


Volume: 8      Da Pagina: 100065-1  A: 100065-12

Parole chiavi: Degenerated four waves mixing; n2-parameter; Neodymium-doped Calcium Fluoride (Nd:CaF2) crystal; Time-resolved digital holography; Ytterbium-doped Yttrium Aluminium Garnet ceramic
DOI: 10.1016/j.omx.2020.100065