The Study Of Photorefractive Grating Filier And Its Application

With the development of the optical communication technology, grating filter is playing an increasingly important role as an essential key component of wavelength division multiplexing (WDM) optical networks. In this thesis, photorefractive grating filter based on lithium niobate (LiNbO3) and its application are researched.First, Ti:LiNbO3 waveguide bonding with fibers is achieved. With the use of the stereo microscope and six-dimensional adjustment racks, the waveguide was successfully bonding with fibers by optical adhesive in the cleanroom. The result measured by power meter shows that the input power is 13.19 dBm and the output power is -18.04 dBm. It just meets the requirements of the follow-up experiment. And it provides the experimental basis for the production of Ti:LiNbO3 waveguide photorefractive grating.Secondly, the photorefractive grating was successfully written in the fiber pigtailed Ti:LiNbO3 waveguide by the method of two-beam interference. In the experiment, the power of two beams is 373.8 mW and 227.6 mW respectively and the interference time is 10 minutes. Filtering effect of the grating can be obtained by a spectrometer detector. The filter center wavelength is 1555 nm with a bandwidth of 1 nm and a depth of 1.5 dBm.Finally, the basic structure and the working principle of the optical add/drop multiplexer based on Ti:LiNbO3 waveguide with long-period photorefractive gratings were presented. The simulation was achieved in the OptiBPM software according to the structural parameters. And the simulation results were normalized by Matlab. The transmission spectrum of 100% coupling at the resonant wavelength of 1553nm was presented. The finally efficiency coupled into the receiving waveguide was about 14.8%.