And the recording material used in this section is a Bayfol HX102 photopolymer. (Wavelength selectivity (HWFZ) of transmitting volume gratings at λ = 532 nm and n 0 = 1.5 on spatial frequency for optimal refractive index modulation with grating thickness in 0.5, 2, 5, and 10 mm.In reflection volume grating, the fringes are more or less parallel to the surfaces of the recording material, and the incoming “reference” wave (R) and the outgoing “signal” wave (S) are on the same side of the recording material. In this chapter, the basic theories and the specific analysis for the full-color holographic optical element are explained. And the optimum recording intensities for each wavelength were experimentally investigated by analyzing the non-response time of the recording materials. Normal incidence, λ = 532 nmand n 0 = 1.5.The angular selectivity of unslanted reflection volume grating could be determined by substituting Eqs. [Schematic diagrams of the transmission hologram for the HOE solar concentrator on the photopolymer film.In solar concentrator systems, the sun tracking systems are necessary owing to the movement of the planet. Analog holography requires re-cording a fresh hologram for each object. And the iterative exposure time method is complicated in the recording process. The photopolymer has the fastest response in the red wavelength and the slowest response in the blue wavelength, so a full-color HOE should be recorded with different recording intensities.The characteristics of the photopolymer have significant effects on the many applications. proposed a reflection-type HOE with high diffraction efficiency for a waveguide-type HMD using a photopolymer and present a laminated structure method for fabricating full-color HOE [Efficiency of the full-color HOEs for (a) combined structure, (b) three-layer laminated structure, and (c) two-layer composited structure.In this experiment, the diffraction efficiencies of the photopolymer were more than 90% for each R, G, and B color that provides wide angular selectivity.
Contact our London head office or Our team is growing all the time, so we’re always on the lookout for smart people who want to help us reshape the world of scientific publishing.Holographic optical element is widely developed in augmented reality, virtual reality, and three-dimensional display application.
The total field within the grating is written as follows:Vector diagram: (a) the relation between the propagation vector and the grating vector, (b) near at Bragg condition, and (c) exact Bragg incidence.For fixed wavelength, the Bragg condition may be broken by angular deviations that relates the angular selectivity to the wavelength selectivity of a volume hologram grating; small changes in the angle of incidence or the wavelength have similar effects.
It’s based on principles of collaboration, unobstructed discovery, and, most importantly, scientific progression. The full-color HOE with enhanced diffraction efficiencies using the optimum recording intensities for each wavelength will be presented.
and Kasai et al.
Publishing on IntechOpen allows authors to earn citations and find new collaborators, meaning more people see your work not only from your own field of study, but from other related fields too.Brief introduction to this section that descibes Open Access especially from an IntechOpen perspectiveWant to get in touch? In order to realize the effective sun tracking system, an interval within 10 am–2 pm is widely used, as shown in Schematic diagram for angular multiplexed holographic solar concentrator.The iterative recording method is used to improve efficiency and uniformity. Therefore, it is investigated in various fields, such as optical device, communication, and display. Through the optical system, it can measure the shifted angle from the Bragg angle, and then calculate the compensated value to record the hologram with the new recording angle.Shrinkage and compensation diagram in reflective recording structure.The shrinkage of the recording materials is calculated bywhere d is the thickness of the material, and d′ is the thickness of the material after recording the grating. So, the optimum recording intensities for each wavelength were experimentally investigated to record the three wavelengths at the same time.