Collinear phase-matching loci of LBO crystal in three-wave interactions

By choice of a reliable dispersion relation of LBO crystal, the loci of LBO crystal in second harmonic generation and sum-, difference-frequency generation (three wave interactions) are presented over its entire transparency region for the first time, on the basis of a new topological classification of phase-matching direction loci in biaxial acentric crystals. The result shows that there are totally 7 loci and 9 transitions for second harmonic generation, 12 loci and 15 transitions for three wave interactions at the room temperature 20 °C. The temperature dependence of LBO yields that the noncritical phase-matching loci of second harmonic generation varies slowly in the range of 20–300 °C, while the phase-matching loci in three wave interactions demonstrate varying locus distribution in the spectral region with temperature.