Programmable optical guided-wave device using Bi12SiO20crystal

A new type of optical guided wave device, consisting of two-dimensional optical refractive-index patterns that can be written in and erased optically, is proposed and demonstrated. This programmable optical guided-wave device utilizes the combination of three physical properties of bismuth silicon oxide (Bi
12
SiO
20
) crystal: a large electrooptic effect, a strongly wavelength-dependent photoconductivity effect, and a high dark resistivity with long carrier trapping time.