DC-induced generation of the reflected second harmonic in silicon

DC-induced generation of the reflected second harmonic is experimentally observed on the surface of a centrosymmetric silicon single crystal. A direct current with a surface density of j (max) similar to 10(3) A/cm(2) violates the symmetry of the electron distribution function and induces the optical second harmonic with an intensity corresponding to the dipole quadratic susceptibility chi((2)d) (j (max)) similar to 3 x 10(-15) m/V.