Study On The Characteristics Of Holographic Materials And Holographic Display Technology

With the development of technology and improvement of living standard of human beings,traditional ordinary two-dimensional display devices are no longer expected while novel three-dimensional(3D)model of the display technology is full of expectations.Among these novel display technologies,holographic display is considered a true 3D display technique because it is capable to record and reconstruct both the intensity information and the phase information of an object or scene.However,there are many problems to realize holographic display,the computer generated hologram technology is limited by pixel size of spatial light modulator.In this paper,we introduce a holographic photopolymer and a liquid crystal which is suitable for dynamic holographic display.The main contents of this paper include three aspects as following:First,study on permanent holographic recording in trimethylol propane triacrylate-based photopolymer films with high diffraction efficiency.The diffraction efficiency ~90% can be achieved without electric field applied.It has many advantages as a holographic storage medium of high resolution,high diffraction efficiency,high photosensitivity,and stability.This material can absorb visible light in the wavelength range of 450-600 nm.The relationship between the diffraction efficiency and the recording angle,intensity of recording beams and exposure time was studied to form the best experimental condition of recording.Then,in this paper we verify the properties of holographic recording and information storage capability of this photopolymer.After the optimal exposure parameters are determined,many kids of interferometric holograms are recorded in polymer films.Firstly,two-beam coupling was used to record grating and eight holograms are stored at a single location by method of angle multiplexing.Secondly,we also have built a gratings direct-writing system for further validating the performance of this material,and the grating structure recorded in polymer films can be observed under the scanning electron microscope.Thirdly,we build image recording system for holographic printing experiment and storage stereo-holograms,and the formation process of multiple volume holograms was presented.Fourthly,a coaxial holographic recording setup is built for simulate holographic recording of real 3D objects.Finally,computer-generated hologram is used to reconstruct 3D object,and the wavefront information of the 3D object can be recorded and reconstructed by polymer films.Above experiments demonstrate that this polymer film exhibits good performance in analog hologram,digital hologram and big data permanent storage.This polymer material may be applied to the arts,medical imaging,advertising,information storage,digital hologram print,analog hologram recording,holographic anti-counterfeiting techniques and other fields.At last,according to the performance requirements,we choose two kinds of azo dye doped liquid crystal with different molecular structure,results showed that total time to establish and erase a holographic grating is less than 40 ms,so it can be used as a real-time dynamic holographic display material.