4. Conclusion

HOE is an optical device able to include a variety of features in a transparent thin film or plastic. The biggest advantage of HOE is that the traditional optical element or the multifunctional devices which does not exist can be produced on single HOE. Therefore, it is investigated in various fields, such as optical device, communication, and display. Nowadays, the usage of 2D holographic projection screen is increased in advertisement, performance, AR fields, and so on, and the development trend of holographic 3D screen is turned into HMD from 3D TV. It has been certified that the HOE is much useful and an effective technique especially for simplified optical systems. In order to develop the HOE more practical and applicable, the manufacturing system for recording medium and the lossless replication technology for mass production are required. However, only few materials that are applicable in replication technology are suggested, and the perfect solution for replication technology has not been completed yet. Therefore, the medium recording and replication technology should be developed continuously, and the main issues of the full-color HOE, color uniformity, and chromatic aberration need more researches.
