Mid-infrared tunable, narrow-linewidth difference-frequency laser based on orientation-patterned gallium phosphide

7th International Symposium and Young Scientists School "Modern Problems of Laser Physics"

Insero, G.^1,2 ; Clivati, C.^3 ; D'Ambrosio, D.^3 ; De Natale, P.^1,2 ; Santambrogio, G.^1,2,3 ; Schunemann, P.G.^4 ; Borri, S.^1,2 ; Zondy, J.J.^5

Istituto Nazionale di Ottica, INO-CNR, European Laboratory for Nonlinear Spectroscopy, LENS, via N. Carrara 1, Sesto Fiorentino

50019, Italy^1

Istituto Nazionale di Fisica Nucleare, INFN, Sezione di Firenze, via G. Sansone 1, FI, Sesto Fiorentino

50019, Italy^2

Istituto Nazionale di Ricerca Metrologica, INRIM, Strada delle Cacce 91, Torino

10135, Italy^3

BAE Systems, Inc., MER15-1813, P.O. Box 868, Nashua

NH

03061-0868, United States^4

Nazarbaev University, School of Science and Technology, Physics Department, Kabanbay Batyr 53, Astana

010000, Kazakhstan^5

关键词: Absolute measurements;    Difference frequency;    Difference-frequency generation;    Effective nonlinear coefficient;    Multiple reflections;    Nonlinear coefficient;    Nonlinear susceptibilities;    Temperature dependent;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/793/1/012012/pdf
DOI  :  10.1088/1742-6596/793/1/012012

来源: IOP

【 摘 要 】

We report on the first characterization of orientation-patterned gallium phosphide (OP-GaP) crystals used to generate narrow-linewidth, coherent mid-infrared (MIR) radiation at 5.85μ by difference frequency generation (DFG) of continuous-wave (cw) Nd:YAG laser at 1064nm and diode-laser at 1301nm. By comparison of the experimental absolute MIR efficiency versus focusing to Gaussian beam DFG theory, we derive an effective nonlinear coefficient d = (1/2)x(2)eff=17(3) pm/V for first-order quasi-phase-matched OP-GaP at the generated DFG wavelength. Using d = (2/π)s14and taking into account Millers delta rule, we retrieve an absolute value of the d14quadratic nonlinear susceptibility coefficient of GaP of d14= 27.2(3) pm/V at 5.85 μ, in good agreement with the latest absolute measurement of this nonlinear coefficient from non-phase-matched second-harmonic generation (1.32 μ → 0.66 μ) taking into account multiple reflection effects [Shoji et al 1997 J. Opt. Soc. Am. B 14 2268]. The temperature and signal-wave tuning curves are also in qualitative agreement with a recently proposed temperature-dependent Sellmeier equation for OP-GaP when focusing effects are taken into account.