HIGH-RESOLUTION MAP OF THE DC ELECTRIC-FIELD IN 2ND-HARMONIC-GENERATING GLASS

Irradiating a glass sample with intense light at both the fundamental frequency omega and its second harmonic 2 omega can rearrange charges in the glass and so produce a strong, semipermanent de electric field inside the This spatially periodic dc field transforms the glass into a phase-matched frequency doubler. We demonstrate a new technique for mapping the spatial distribution of this de electric field with high resolution, and we show that the underlying charge distribution is well approximated by the derivative of a Gaussian.