Temperature-dependent phase-matching properties of BaGa2GeS6 in the 0.767-10.5910 µm spectral range.

We report experimental results on the temperature-dependent phase-matching properties of BaGa2GeS6 for second-harmonic generation and sum-frequency generation in the 0.7674-10.5910 µm range. We also derive refined Sellmeier and thermo-optic dispersion formulas that provide a good reproduction of the present experimental results.

Thermo-optic dispersion formula for LiGaS2.

This paper reports on new experimental results on the temperature-dependent phase-matching properties of LiGaS2 for second-harmonic generation and sum-frequency generation in the 0.820-10.5910 µm spectral range. In addition, we present a thermo-optic dispersion formula that provides a good reproduction of the present experimental results when combined with the Sellmeier equations presented in our previous paper, Kato et al. [Opt. Lett.42, 4363 (2017)OPLEDP0146-959210.1364/OL.42.004363].

Wide-bandgap nonlinear crystal LiGaS2 for femtosecond mid-infrared spectroscopy with chirped-pulse upconversion.

Femtosecond time-resolved mid-infrared (MIR) spectroscopy based on chirped-pulse upconversion is a promising method for observing molecular vibrational dynamics. A quantitative study on nonlinear media for upconversion is still essential for wide applications, particularly at the frequencies below 2000 cm-1. We evaluate wide-bandgap nonlinear crystals of Li-containing ternary chalcogenides based on their performance as the upconversion medium for femtosecond MIR spectroscopy. The upconversion efficiency is measured as a function of the MIR pulse frequency and the chirped pulse energy. LiGaS2 is found to be an efficient crystal for the upconversion of MIR pulses in a wide frequency range of 1100-2700 cm-1, especially below 2000 cm-1. By using LiGaS2 as an efficient upconversion crystal, we develop a MIR pump-probe spectroscopy system with a spectral resolution of 2.5 cm-1, a time resolution of 0.2 ps, and a probe window of 120 cm-1. Vibrational relaxation dynamics of CO stretching modes of Mn2(CO)10 in cyclohexane and bovine serum albumin in D2O are demonstrated with a high signal-to-noise ratio.

Phase-matching properties of yellow color HgGa2S4 for SHG and SFG in the 0.944-10.5910 µm range.

We report new experimental results on the phase-matching properties of yellow color HgGa2S4 crystals for harmonic generation of an Nd:YAG laser-pumped KTiOPO4 (KTP) optical parametric oscillator (OPO) and CO2 lasers in the 0.944-10.5910 µm range. In addition, we present new Sellmeier equations that provide a good reproduction of the present experimental results as well as the published data points for second-harmonic generation of CO2 laser radiation at 9.2197-9.6392 µm and Nd:YAG laser-pumped OPOs at 1.205-1.725 µm and 2.77-9.10 µm that were achieved with the orange and yellow color crystals.

Sellmeier and thermo-optic dispersion formulas for the extraordinary ray of 5 mol. % MgO-doped congruent LiNbO(3) in the visible, infrared, and terahertz regions.

This paper reports the high-accuracy Sellmeier and thermo-optic dispersion formulas for the extraordinary ray of 5 mol. % MgO-doped congruent LiNbO(3) that provide excellent reproduction of the temperature-dependent quasi-phase-matching conditions in the 0.39-4.95 µm and 150-270 µm ranges. We believe that these equations would be highly useful for designing the frequency conversion system based on periodically poled MgO-doped LiNbO(3)

Sellmeier and thermo-optic dispersion formulas for LiInSe2.

This paper reports on the improved Sellmeier and thermo-optic dispersion formulas for LiInSe2, which provide a good reproduction of the temperature-dependent phase-matching conditions for the nonlinear frequency-conversion experiments achieved in the 1.0642-10.5910 µm range.

Sellmeier and thermo-optic dispersion formulas for LiInS(2).

This paper reports on improved Sellmeier and thermo-optic dispersion formulas for LiInS2, which provide an excellent reproduction of the temperature-dependent phase-matching conditions for second, sum-, and difference-frequency generation achieved in the 1.0642-10.5910 µm range.

Sellmeier and thermo-optic dispersion formulas for GaSe (Revisited).

This paper reports high-accuracy Sellmeier and thermo-optic dispersion formulas for GaSe that provide excellent reproduction of the phase-matching conditions for second-, third-, and fourth- harmonic generation of CO2 laser radiation at 10.5910 µm in the 20°C-200°C range as well as the data points of Feng et al. [Opt. Express16, 9978 (2008)10.1364/OE.16.009978OPEXFF1094-4087] for second-harmonic generation of CO2 laser radiation at 9.5862 µm and an Er3+:YSGG laser at 2.7960 µm in the -165°C-230°C range.

Sellmeier equations for GaS and GaSe and their applications to the nonlinear optics in GaSxSe(1-x).

The Sellmeier equations for GaS and GaSe are constructed from the nonlinear experiments thus far reported in the literature. The model calculations based on these equations were found to reproduce well the phase-matching conditions for second-harmonic generation of the Er:YSGG laser at 2.7960 µm and the CO2 laser lines at 9.5862 and 10.5910 µm achieved in the GaSxSe(1-x) crystals having different S concentrations of 0.004-0.412.

Simultaneously phase-matched blue and red light generation using BIBO.

BiB3O6 has been found to be simultaneously phase matchable for sum-frequency generation at 0.4627 and 0.6260 microm by mixing the outputs of a 0.5321 microm pumped parametric oscillator with the fundamental source at 1.0642 microm. The simultaneous blue and red light generation is achieved under the temperature-insensitive phase-matching condition, and the relative strength of blue and red light can be controlled by changing the effective nonlinear constants through the azimuth angle. In addition, wide wavelength tuning of the simultaneous phase matching is obtained by the use of a noncollinear geometry, enabling a compact red-green-blue laser system based on the powerful solid-state laser.

Phase-matched pure chi((3)) third-harmonic generation in noncentrosymmetric BiB3O6.

Third-harmonic generation (THG) has been investigated in the monoclinic BiB(3)O(6). The symmetry and birefringence analysis revealed that there are phase-matching conditions for the direct third-order nonlinear process, where the cascading second-order processes are precluded by the zero effective nonlinearity. The first phase-matched pure chi((3)) THG in a noncentrosymmetric crystal is presented together with the improved Sellmeier and thermo-optic dispersion formulas.

Temperature phase-matching properties for harmonic generation in GdCa4O(BO3)3 and Gd(x)Y(1-x)Ca4O(BO3)3.

GdCa4O(BO3)3 has been found to have phase-matching points where the temperature variations of the phase-matching angles become zero for type-1 sum-frequency generation in the zx plane. We also found that the temperature sensitivities of the phase-matching conditions in the zx plane are different along the phi = 0 degrees and phi = 180 degrees directions in this material. In addition, the thermo-optic dispersion formula of this material that reproduces the temperature phase-matching properties of GdCa4O(BO3)3 and Gd(x)Y(1-x)Ca4O(BO3)3 is presented.

200-mW-average power ultraviolet generation at 0.193 microm in K2Al2B2O7.

K2Al2B2O7 has been found to be phase matchable for type-1 sum-frequency generation (SFG) at 0.193 microm by mixing the Nd:YAG laser wavelength at 1.0642 microm and the SFG output of the RbTiOAsO4 optical parametric oscillator tuned at 0.2358 microm. An average power of 200 mW at 10 kHz was obtained in a 7-mm-long crystal. In addition, the Sellmeier equations and the thermo-optic dispersion formula, which predict well the phase-matching conditions and temperature phase-matching bandwidths (FWHM) for second-harmonic generation and SFG in the 0.193-0.669-microm range, are presented.