… We demonstrate UV poling of a pure fused silica sample by applying to it an electric field of
200 kV/cm and irradiating it with high-intensity ( ∼ 40 GW ∕ cm 2 ) femtosecond (220 fs) laser
pulses at 264 nm. … In this investigation, we tried to repeat Fujiwara’s experiments using a
high-intensity UV femtosecond laser source and undoped fused silica samples, excited by a
two-photon mechanism. After irradiation, we observed a strong second-harmonic (SH) signal
in the areas of the sample that had been subjected both to the electric field and to the UV light. …

… We demonstrate UV poling of a pure fused silica sample by applying to it an electric field
of 200 kV/cm and irradiating it with high-intensity 40 GW/cm2 femtosecond 220 fs laser
pulses at … 7,8 After irradiation, we observed a strong second-harmonic SH signal in the
areas of the sample that had been subjected both to the electric field and to the UV light.
The experimental setup is shown in Fig. 1. …