Generation of terahertz radiation by bulk and surface optical rectification from crystal planes of arbitrary orientation

The theory of second-order nonlinear bulk and third-order nonlinear surface electric-field-induced optical rectification is developed for zinc-blende 4¯3m crystal faces of arbitrary indices (hkl). The theory is then used to account for our experimental results for terahertz generation from GaAs high-index planes (11N)A and (11N)B, where N=2, 3, 4, and 5. The data combined with the calculations allow us to demonstrate that a surface field is present on both the Ga-rich and As-rich faces and to determine that the signs are opposite and that the strengths are similar. Such conclusions are inaccessible by work restricted to low-index planes.