Visualization of electric field of e-beam-formed charge patterns in glass

We have formed a given pattern of the second order optical nonlinearity in the
subsurface region of a glass by electron irradiation. The nonlinearity was induced by the electric
field of the electrons captured by the glass. Formed structure consisted of periodic «strips» and,
being irradiated normally to the glass surface with an IR laser, generated the second harmonic
(SH) radiation pattern similar to one of a phase diffraction grating. The pattern presented the
results of an interference of the SH waves generated by nonlinear strips. Mapping of the SH
radiation pattern in orthogonal polarizations of the fundamental laser beam allowed concluding
about the distribution of the electric field of electrons captured in the glass.