New experimental results for SHG and DFG in AgGaGeS4

This paper reports the experimental results on the phase-matching properties of AgGaGeS4 for second-harmonic generation (SHG) at 0.8 &mgr;m that was achieved by using the KTP optical parametric oscillator and difference-frequency generation (DFG) at 2 and 5-12 &mgr;m that were achieved by using the dual-wavelength emitting Ti:Sapphire laser and the Nd:YAG laser. Two AgGaGeS4 samples showed locally different phase-matching conditions which were probably caused by the various crystal compositions. The new Sellmeier equations were constructed using the literature value of the refractive indices and compared with the experimental data. A satisfactory agreement between the model calculation and the experiments is obtained.