Accordabilité thermique des interactions ONL: formalisme vectoriel et applications à HGS, KTP et RTP

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Thiogallate de mercure (HgGa2S4) : un cristal pour les OPO dans le moyen infrarouge

Comprehensive formulation of temperature-dependent dispersion of optical materials: illustration with case of temperature tuning of a mid-IR HgGa_2S_4 OPO

The temperature dependence of refractive indices of optical materials is characterized in this work by what we call their normalized thermo-optic coefficients. These are determined experimentally through interferometric measurements of thermal expansion and of changes in optical thickness at a few laser wavelengths as function of temperature. A suitable vectorial formalism applied to these data allows predicting the thermal evolution of the refractive index all over the useful range of transparency. The validity and reliability of our methodology is demonstrated through temperature tuning of a mid-IR HgGa2S4 optical parametric oscillator (OPO) pumped at 1.0642 μm by a Nd:YAG laser. Measured…

Comprehensive formulation of the temperature dependent dispersion of optical materials; illustration with the case of temperature tuning of a mid-IR HgGa2S4 OPO

International audience; The temperature dependence of refractive indices of optical materials is characterized in this work by what we call their normalized thermo-optic coefficients. These ones are determined experimentally through interferometric measurements of thermal expansion, and changes in optical thickness at a few laser wavelengths as function of temperature. A suitable vectorial formalism applied to these data allows predicting the thermal evolution of the refractive index all over the useful range of transparency. The validity and reliability of our methodology is demonstrated through temperature tuning of a mid-IR HgGa2S4 OPO, pumped at 1.0642 μm by a Nd:YAG laser. Measured the…

Thermal expansion, normalized thermo-optic coefficients, and condition for second harmonic generation of a Nd:YAG laser with wide temperature bandwidth in RbTiOPO_4

Interferometric determination of thermal expansion and of normalized thermo-optic coefficients of RbTiOPO4 at four laser wavelengths are performed as a function of temperature. A suitable vectorial formalism applied to obtained data allows the establishment of the temperature dependence of refractive indices, and subsequent theoretical analysis enables one to predict that an extremum in the evolution of the phase-matching direction in the (X,Y) plane should occur near 100 °C for type II second harmonic generation of Nd:YAG lasers, with a temperature bandwidth that can be as large as 117 °C for a crystal of 10 mm in length. Such unusual behavior is observed experimentally by recording the co…

Dispersion and temperature dependence of thermo-optic coefficients of optical materials over their whole transparency range: vectorial formalism and application to KTiOPO4 and HgGa2S4