Abstract

Glass is an ideal optical material because it is wonderfully transparent, inexpensive, and can be readily fabricated into optical waveguides. Unfortunately, glass is a less-than- ideal nonlinear material. In its natural state glass has inversion symmetry, which precludes its having any second-order nonlinearity [χ⁽²⁾ = 0]. Lacking a second-order nonlinearity, ordinary glass cannot frequency double light or electro-optically modulate a laser beam. In recent years, however, researchers have learned how to create a strong dc electric field inside glass. This dc electric field breaks the glass’s inversion symmetry in one direction, and so enables the glass to act as a frequency doubler or electro-optic modulator.

© 1994 Optical Society of America