2ND-ORDER OPTICAL NONLINEARITY IN CORONA-POLED GLASS-FILMS

Several experiments were performed to elucidate the origin of the seco nd-order optical nonlinearity chi(2) induced in the corona-poled Comin g 7059 glass films. The values and the time decay of the second-harmon ic coefficient d33 were measured for the glass films poled on several different kinds of substrates. The value of d33 Was found to be depend ent on the kinds of substrates. It was also observed that the glass fi lms poled on a soda-lime substrate showed faster time decay of d33 tha n those poled on a Pyrex glass substrate. The glass films were also po led at room temperature, and the values of d33 were measured as a func tion of poling time. As a result, the value of d33 increased with the poling time and approached a value which was close to that obtained fo r the glass films poled at 100-degrees-C. From the experimental result s, it is speculated that the space charge formed in the vicinity of th e interface between the glass film and the substrate contributes to th e creation of the chi(2). The planar charge density at the glass-film- substrate interface is derived, and the experimental results are discu ssed.