Second-harmonic generation in germanosilicate glass poled with ArF laser irradiation

We report on a remarkably large second-harmonic generation (SHG) in a germanosilicate glass 15.7 GeO2-84.3 SiO2 in mol %), which was induced by poling while the sample was irradiated with the ArF laser at the wavelength of 193 nm. The SHG coefficient, d, thus induced was measured at various poling electric-field strengths using the Maker-fringe technique. The value of d increases with increasing poling field and then saturates around 1.5x10(5) V/cm. The largest d coefficient value obtained in this work, which is 3.4+/-0.3 pm/V, seems to exceed d(22) of LiNbO3. Furthermore, polarization dependence of the induced SHG shows an anisotropy of the refractive index. (C) 1997 American Institute of Physics.