Barium nonlinear optical crystals for the mid-IR: characterization and some applications

The linear and nonlinear optical properties of B a G a 4 S 7 , B a G a 4 S e 7 , B a G a 2 G e S 6 , and B a G a 2 G e S e 6 are reviewed, highlighting their potential for frequency downconversion of powerful laser sources from the near- to the mid-IR. Examples of successful applications are summarized and briefly discussed.