Investigation Of An Optical Switching For OXC Based On Volume Holographic Grating

OXC, Optical cross Connector, is one of the most important technologies in AON,and one of its core technology is high powered optical switching which can be used for OXC . And a new optical switching which can be used in OXC has been looking forward to base on volume photographic technology in this thesis.First, the properties of volume holographic gratings, such as the diffraction efficiencies has been analyzed theoretically, as well as angle, wavelength and wave front phase selectivity. And then the grating established by the gauss laser beam is deduced. The fundamental principle that photorefractive volume grating is used to make OXC optical switching is presented. The key technologies in making the optical switching, such as selection of recording material, method or encoding and recording geometry are studied further. The conclusions indicate that:LiNbO3: Fe should be considered first as the holographic optical switching recording material, due to its advantages of available large crystal sizes, big storage capacity, long storage lifetime, high diffraction selectivity and high diffraction efficiency.In order to gain higher diffraction efficiency and higher selectivity sensitivity, extraordinary polarization geometry configuration should be applied. However, ordinary polarization recording geometry configuration is more property to gain better uniformity of diffraction efficiency.Double wavelength method is the way to make the usage of photorefractive grating switching in optical communication possible. The optical gratings are recorded by those beam whose wavelengths are photorefractive effect hypersensitive, and read out by the infrared wavelengths.Further, a new encode method which is phase-wavelength encode method is put forward. And an experimental scheme of 2 wavelengths and 4-path holographic optical switching is designed.