The numerical reconstruction process is based on the fresnelkirchhoff integral, which describes the diffraction of the reconstructing wave at the microstructure of the hologram. Aic image construction of burning propellants in both strand and twodimensional cross flow. The video lecture will explain how a hologram is made. Single shot digital holography using iterative reconstruction with alternating updates of amplitude and phase dennis j. Review of digital holography reconstruction methods.
Reconstruction of a complex object from two inline holograms. The interference pattern is captured by the film and processed. This read out bream illuminates the hologram at the same angle as the reference beam. That point therefore constitutes a substantially fixed apparent beam source position which remains stationary relative to the film over which the beam is scanned. The reproduction of the image from the hologram is known as reconstruction of the hologram. Holography is the science of making holograms which are usually intended for displaying three dimensional images. In conventional photography, a negative is made first and using it a positive print is produced later. In this process,a wave identical to reference beam is used. The discussion in this chapter will also make clear the need for a cylindrical shaped hologram, and explain its advantages and disadvantages. At that time, scanning devices that could be used for digitizing holograms, had low resolution, which required optical magnification of holograms to. Direct recording of holograms by a ccd target and numerical reconstruction u. This rubric is very useful in many applications including robot navigation, terrain modeling, remote surgery, shape analysis, computer interaction, scientific visualization, movie making, and computer aided design. Holography 1 holography introduction and background the. A laser light hologram is recorded and reconstructed by using the same laser light as for recording.
Precision and planning are key to reconstructive surgery. The sampling pitch of the reconstructed field is the same as that. The reconstruction of the object field encoded within the hologram is based on the principle of light diffraction. Construction and reconstruction of image on hologram. Recording and reconstruction process in holography winner. The novel system introduces the reference light and the virtual object light and let them impinge upon a screen, and then the interferogram is obtained on the screen. Fourier relations between antenna aperture distributions. Digital hologram reconstruction of radio telescope data peter kellman, steve leonard, and eamon barrett esl, incorporated, 495 java drive, sunnyvale, california 94086.
The reconstruction beam after passing through the hologram produces a real as well as virtual image of the object. Construction and reconstruction of image on hologram for engg. A hologram is a physical recording of an interference pattern which uses diffraction to. Construction and reconstruction of image on hologram in holography the process of image formatter consist of two types. We believe that better reconstructions of objects can be achieved by considering the hologram re construction as an inverse problem, as in 5. In some instances of definition, it is as important to clarify what you are not describing as what you are. The recording and reconstruction setups for a transmission and b reflection. Digital recording and numerical reconstruction of holograms. In this paper, we pro pose a new numerical reconstruction approach using a statistical technique. The geometry of recording and reconstruction of a hologram in this analysis. The hologram was also reconstructed using the cepstrum technique proposed in this paper. The details of a software implementation of a digital hologram reconstruction methods are presented. Holography is the recording construction of wavefront inter ference patterns created by coherent laser light sources and the replay reconstruction of these patterns as visual images or other forms of wave media.
Holography, on the other hand does not utilize a lens to form a latent image. Explain why the images of holograms are truly three dimensional. Know how to reconstruct the real and the virtual images from a transmission hologram. A real image of the object is reconstructed from the digitally sampled hologram by means of numerical methods. Discussion we have described an algorithm for penalizedlikelihood re construction in for digital holography that is an alternative to the method described in 2. A technical term for holography is wave front reconstruction universalhologram, 2009. Weiner 1sandia national laboratories, 1515 eubank blvd. More complete discussions of the theory are in references 1, 2, 3. Pdf holography is the science of making holograms which are usually intended for displaying three dimensional images. This reconstruction beam will undergo phenomenon of diffraction during passage through the hologram. Dec 05, 2017 this is small topic of engineering physics. Anew method for resolution control in numerical reconstruction of digital holography is proposed. In this paper, we propose a new technique for highquality reconstruction from single digital holographic acquisitions.
Because holographic image re construction is an illposed problem, our statistical. Realtime construction and reconstruction of fresnel holograms is demonstrated using an opticallyaddressable ferroelectric liquidcrystal spatial light modulator. We then discuss the accuracy of the proposed procedure for the estimation of both 3d position and. Unclassified ad number ad474534 new limitation change to approved for public release, distribution unlimited from distribution authorized to u. The phases of the stored light waves can be calculateddirectly from the digital holograms, without. Pdf 3d volume reconstruction using hologram researchgate. Field reconstruction of holograms for interactive free.
Therefore, reconstruction of the image occurs when the reference beam diffracts off the interference pattern. A hologram is a photographic recording of a light field, rather than an image formed by a lens. The principle of recording holograms directly on a ccd target is described. Holography 1 holography introduction and background the aesthetic appeal and commercial usefulness of holography are both related to the ability of a hologram to store a threedimensional image. Introduction first experiments in numerical reconstruction of optical holograms date back to 196070th. Unlike ordinary photographs, holograms record both phase and amplitude information. Numerical reconstruction of digital holograms with variable. Although this approach is a general approach, the proposed toolbox is limited to 3d reconstruction of in line digital holograms of spherical microobjects, typically droplets or bubbles. Many methods exist for the recording and playback of a hologram, and a simple apparatus is shown in figure 1 and figure 2. Jul 31, 2012 construction and reconstruction of image on hologram in holography the process of image formatter consist of two types. Thus the total phase at the hologram, on reconstruction, is. Because phase is a relative property, construction of a hologram requires a reference beam in addition to the light reflected from an objects surface.
For a fair comparison, the reconstruction parameters. Holography is the science and practice of making holograms. The reconstructed phase wavefront emerging from the hologram at x,y in the hologram plane is then calculated as the sum of the recorded phases, r and o and the phase of the reconstructed wave, c. Osa a practical inverseproblem approach to digital. May 04, 1993 the incident light is focussed onto the mirror at this point so that the illuminating beam for the hologram construction always appears to diverge from it. The positive print is only a 2d record of light intensity. The unknown complex object field is found as the solution of a nonlinear inverse problem that consists in the minimization of an energy functional.
Inline hologram reconstruction with sparsity constraints. Field reconstruction of holograms for interactive free space. In the current paper we present a totally new algorithm also based on the two hologram technique. Since j0 is oscillatory rather than monotonic, fringes repre senting contours of constant vibrational amplitude form on the reconstructed image. Pixel resolution control in numerical reconstruction of. Holography holography mathematics proposed by dennis gabor 1948. We report the construction of holograms made from threedimensional, diffusely reflecting ob jects, with reconstruction in full color in ordinary white light derived from a point source, such as, for example, the zirconium arc or an ordinary flashlight. Dynamics after a spatially localized optical excitation pdf. Reconstruction from digital holograms by statistical methods. The advantages and limitations of common wave propagation methods are discussed.
However, its presence degrades the primary wave and prevents getting a high quality hologram. Pdf 3d volume reconstruction technology is the new sign of future technology and communications. Aic image construction of burning propellants in both. Abstractthis research papers examines the new technology of holographic projections. We propose on this web page a matlab toolbox dedicated to inverse problems approach for digital hologram reconstruction. Recording and reconstruction of holograms phywe series of publications laboratory experiments physics phywe systeme gmbh 37070 gottingen, germany 22603 3 index phase hologram. Aberrations in holography triple take holographics. In this letter, we use bayesian framework with a sparsityenforcing. This approach reconstmcts the complex field of the object from the realvalued holo gram intensity data. Reconstruction of image in the reconstruction process, the hologram is illuminated by laser beam and this beam is called reconstruction beam.
Augmented reality ar can bring the information within preoperative computed tomography angiography cta imaging to life, allowing the surgeon to see through the patients skin and appreciate the underlying anatomy without making a single incision. Holography holography mathematics proposed by dennis. Explain the construction and reconstruction of hologram. It highlights the importance and need of this technology and how it represents the new wave in the future of technology and communications, the different application. Here we describe a new method for numerically reconstructing an object with variable viewing angles. Controlling the beam ratio is very important in creating reflection holograms. The hologram is then illuminated with laser light transmission or white light reflection. The hologram in figure 22 was used to illustrate reconstruction by convolution. A method is proposed to compensate this difference by digitally processing the holograms.
For a fair comparison, the reconstruction parameters for both spatial. Osa direct recording of holograms by a ccd target and. It will explain the recording and reconstruction processes in holography. Just like the holographic technique, which can show depth. Recording and reconstruction process in holography. The term hologram is a combination of the greek words holos complete and gram message holography is a process for recording and displaying three dimensional information without lenses therefore holography opens up completely new possibilities in science, engineering, graphics and arts. Schnars and juptner applied their method to interferome. It relies on the principle of interference to produce an image. The process of producing a holographic reconstruction is explained below purely in terms.
It is a physical structure that diffracts light into an image. A technical term for holography is wave front reconstruction universal hologram, 2009. Gabor in 1948, it initially aimed at solving the resolution problem of electron microscope with coaxial holography inline hologram. A laser beam identical to the reference beam is used for reconstruction of the object.
When the hologram is illuminated by the reconstruction wave,2waves are produced. Recording and reconstruction of reflection holograms setup for the creation of reflection hologram is the same as transmission hologram except the reference beam is lit from behind the plate. The latter includes totalvariation tv regularization terms that constrain the spatial amplitude and. Because phase is a relative property, construction of a. Construction of whitelight holographic screens arxiv. Jeong lake forest college lake forest, illinois holography is a much broader field than most people have perceived. Basic principles and applications of holography spie. One wave appears to diverge from the object and provides the virtual image of the object. The incident light is focussed onto the mirror at this point so that the illuminating beam for the hologram construction always appears to diverge from it. A holographic image can be seen looking into an illuminated holographic print by shining a laser through a hologram and projecting a image on the screen. Holography is a technique that enables a light field, which is generally the product of a light source scattered off objects, to be recorded and later reconstructed when the original light field is no longer present, due to the absence of the original objects. In this paper, a digital hologram reconstruction process is investigated. This beam is identical to reference beam used in construction of hologram. In the current paper we present a totally new algorithm also based on the twohologram technique.
A bright holographic image is read out due to the optical separation between the write and read sides by a dielectric mirror. If the holographic plate is illuminated after its development using the same reference wave used in the recording process, the light will diffract into three orders of diffraction if the diffraction network is sinusoidal. When the developed hologram is illuminated by the same reference wave, the reconstructed object wave as was previously emitted from the actual object. The impact on reconstruction quality is analyzed and optimization strategies are evaluated. Gabor, a new microscopic principle, nature 161, 777778 1948. Construction and reconstruction of image on hologram for. Numerical reconstruction of digital holograms with.