In 1960s, Kozma and Kelly combined computer and spatial frequency domain filtering technology to design matched spatial filters artificially 18, which laid the foundation for computer-generated holography. 2c and 2f, has also been presented and applied in many fields, such as quantitative phase imaging and optical metrology 16, 17. In addition, digital holography, which records digital holograms (DHs) by sensors in optical systems and reconstructs optical wavefronts digitally as shown in Fig. Because of these advantages, computer-generated holography is a future-oriented 3D display technology and can be used in many fields, such as education, entertainment, military and medical treatment 14, 15. Compared with optical holography, computer-generated holography can record not only real objects but also virtual objects without complex optical systems and can realize dynamic holographic 3D display with the help of refreshable SLMs 9, 10, 11, 12, 13. In computer-generated holography, the recording process can be simulated by computers and the reconstruction can be realized by loading the computer-generated holograms (CGHs) on the spatial light modulators (SLMs) with coherent light illumination as shown in Fig. With the development of computer and optoelectronic technology, computer-generated holography has become an international research hotpot. Optical holograms (OHs) are usually static holograms and have strict requirements on the stability of the optical systems, which restrict the application of optical holography in dynamic holographic 3D display. The traditional optical holography relies on the optical systems and photosensitive materials to complete recording and reconstruction process as shown in Fig. Rainbow hologram can be reconstructed by white light because it minimizes the blurring caused by the dispersion of the transmission hologram via abandoning the parallax information in the vertical direction. Afterwards, Benton invented the two-step rainbow hologram 8. In the same year, Denisyuk invented the reflection hologram, which can be reconstructed by white light because of the high degree of selectivity to wavelength 6, 7. In 1962, Leith and Upatnieks separated the twin image by increasing the carrier frequency of the reference light, thereby greatly expanding the applicability of holography 3, 4, 5. However, the application of holography was restricted in many years because on-axis holography has inability to solve the problem of the twin image. Due to the invention of holography, Denis Gabor won the Nobel Prize in Physics in 1971. ( 2), which indicates that the original object can be reconstructed successfully. If the reconstruction light Re is chosen as the reference light R, the third term of the diffraction light U is, up to a multiplicative constant, an exact duplication of the original object light O as shown in Eq. In reconstruction process, the hologram is illuminated by the reconstruction light Re. In recording process, the object light O and the reference light R interfere in the hologram plane and the interference fringe I is recorded on the hologram as shown in Eq. Like his name representing the meaning of whole, holography is a technique to record and reconstruct all the physical information of a 3D scene based on interference and diffraction theory as shown in Fig. Holography was invented by Denis Gabor in 1947 to improve the resolution of electron microscopy 2. Among all existing 3D display technologies, holographic 3D display is regarded as the most promising 3D display technology because it can reconstruct all information of a real or virtual scene and bring no visual fatigue 1. In recent years, 3D display technology has attracted more and more attention. However, traditional two-dimensional (2D) display technology can only display a 2D projection image from one side of the three-dimensional (3D) scene, which loses the depth information and affects the 3D spatial information acquisition. Display technology is very important for humans to acquire information.
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