Study On Technique Of Wavelength Demultiplexing With Phtorefractive Multiple Volume Holographic Grating

In this thesis, by contrasting, some advantages and disadvantages of several kinds of techniques of wavelength-division multiplexing (WDM) are indicated respectively. The technology of WDM basis on volume holographic technology is studied. Meanwhile, some theory and implementation method of this technology are discussed. The main wok in the thesis is as following:1. The formation mechanism, diffraction efficiencies and wavelength sensitivity of the photorefractive volume grating in photorefractive crystals are theoretically analyzed. On the other hand, the properties of volume holograms and the filtering principles of multiple photorefractive volume gratings are discussed by using volume holograms theory and Bragg condition.2. The properties of the grating, such as, incident angle to record the grating , channel space, rotation angle, in LiNbO₃:Fe crystal as the device of wavelength-division multiplexing, is discussed in theory. And the relation of the thickness of grating and the minimum channel space is discussed, too.3. By using the inherent angle and wavelength selectivity of the volume gratings in crystal and analyzing diffractive properties of the holographic gratings superimposed in the LiNbO₃:Fe crystal which sample with size of 10*10*10mm³ through angle multiplexing, the feasibility of the new method —the photorefractive multiple volume grating applying in WDM system is proved.