Study On Volume Holographic Storage Of Doped Lithium Niobate

In today's society,with the development of science and technology and the progress of mankind,a huge amount of data has been generated,and the reserve of these data has become a huge problem.Holographic storage has the advantages of large storage capacity,fast transmission and access speed,long storage time,stable and reliable information recording,and the ability to record stereo images and facilitate copying.Therefore,the research on volume holographic storage has received extensive attention.In this paper,holographic storage was studied using doped lithium niobate as the storage medium.The experimental parameters of the doped lithium niobate used in the experiment were first measured,and the optical power threshold of the doped lithium niobate crystal was measured by using the light scattering performance test.After the appropriate optical power was determined,the relationship between the diffraction efficiency and the angle of the beam was tested,and the best storage angle was obtained.Then the experimental optical path was designed and the transmissive and reflective holographic storage experiments were performed.By comparing the experimental results of the two storage methods,the best holographic storage method was analyzed.Finally,analyze the possible noise in the experiment and propose the corresponding solution.The main research results of the paper are as follows:(1)Perform a photo-scattering test on doped lithium niobate,and select optical powers of 0.6 mw,0.7 mw,0.8 mw,0.9 mw,and 1.0 mw for experiments to obtain the optical power threshold of lithium niobate at 1 mw.The selected power was 0.84 mw to test the relationship between the diffraction efficiency and the beam angle.The beam angle was tested from 25° to 80° and the interval was chosen to be 5°.From the relationship of the diffraction efficiency with the angle of the beam,it can be seen that the diffraction efficiency is maximized at an angle of 50°.(2)After the experimental parameters were obtained,holographic storage experiments were performed.Selecting optical power of 0.84 mw and beam angle of 50° for Transmissive holographic storage successfully stored and reproduced clear and complete 2D images.Due to the relatively large angle of the reflective holographic storage beam,the incident angle of the beam has a certain influence on the optical power threshold,so a large-angle light scattering test is performed,and the suitable power value at a large angle of incidence angle is obtained.The experimental optical path was adjusted to perform reflective holographic storage,and 2D images were successfully stored and read out.The diffraction efficiency was lower than that of the transmissive holographic storage.The reason is that the beam angle has a great influence on the optical power threshold of the crystal.After increasing the angle of the beam,the decrease of the threshold makes the diffraction efficiency decrease,and the incident angle of the beam will also change the effective propagation path,thus reducing the coupling gain coefficient of the two waves.Therefore,under the same experimental conditions,the transmissive effect is better than the reflective holographic storage,and it is a more suitable holographic storage method.Finally,the paper analyzes the various noises that may appear in the holographic storage process and proposes corresponding solutions.It will be of great help to the future holographic storage research.