Temperature synchronism width for frequency conversion in BBO crystal

The results of theoretical studies are presented, showing that in a BBO crystal in the entire transparency range there are directions with interactions that are not critical in temperature for three-wave processes. All phase-matched processes for frequency conversion (generation of harmonics, sum and difference frequencies, parametric generation) are temperature-critical, but can be realized with a record-high temperature phase-matching width (up to 150 °C·cm).