Investigation on the second-harmonic generation from the cathode-side face in a poled glass

The authors systematically investigated the second-order susceptibility of the cathode-side face of poled glass. This report consists of three parts. The first is a technique to pole a set of multi-pieces of glasses for distinguishing the second harmonic (SH) signals from the anode-side piece and from the cathode-side piece. The SH signal from the cathode-side piece was only one hundredth of that from the anode-side piece, and those from the middle pieces are further less. The SH signal increased with the number of glasses in a set. The second is a technique to give a further identification of the SH signals from each face. For this purpose, we looked for the materials, which are opaque to the second-harmonics. We found two kinds of new materials: lead silica and Pyrex glasses. They don't transmit the UV light, but transmit the visible light. We detected the second harmonics at 266 nm from the face of the glass facing to the detector. The SH signal in poled lead silica increased exponentially with the increase in the lead percentage. The third is a new technique of doping F- into the cathode-side face, which increases the SH signal from the cathode-side face by two orders. It reached two times of that from the anode-side face.