Demonstration of dimensional control and stabilization of second harmonic electro-optical response in chalcogenide glasses

Second-order optical susceptibility, χ(2), has been induced in thermally poled chalcogenide glasses, doped with varying levels of sodium. Using alkali-doped chalcogenide glasses, the second harmonic generation (SHG) capability is retained for over a year whereas in alkali-free glasses it disappears in days. The enhanced stability is attributed to a stabilization of the space charge through structural re-arrangements. Polarization-resolved SHG shows that the induced electric field has components in three spatial directions, all with varying extents of stability. Using structured electrodes, we demonstrate the ability to control the various electric field components' geometry, location and stability to realize a long-lived, nonlinear grating in an alkali-doped chalcogenide glass.