Nonlinear optical processes in domain structures of strontium tetraborate

The random quasi-phase-matching in irregular domain structures of strontium tetraborate has been investigated for nonlinear optical generation at 266 nm. The factor of increasing second-harmonic generation efficiency due to random quasi-phase-matching is determined. The spectral dependences of the second-harmonic generation are calculated. It is shown that its efficiency can be optimized at a fixed pump wavelength by rotating the domain structure.