Analytical Laser 3D Holographic Technology

Here is the title one h1 placeholder text

2021-02-10

Laser holography is an important part in the field of modern optical information processing. The hologram (Hologram) was proposed by Gabor in 1948 to improve the image quality of the electron microscope, and its meaning is a complete record. Gaber's experiments solved the fundamental problem in the invention of holography, namely the recording and reproduction of wavefronts, but the imaging quality of holograms was poor due to the lack of a bright coherent light source (laser) at the time. With the advent of laser in 1962, off-axis holography was invented by introducing the concept of carrier frequency on the basis of Gabriel holography, which effectively overcome the main problem of poor hologram imaging quality at that time-twin image, three-dimensional object display became the focus of holography research at that time, but this imaging science far exceeded the economic development at that time, and the cost of making and observing this hologram was very expensive, holography has basically become synonymous with the high cost of maintaining unrealistic illusions.
Principles of 1. 3D technology
(I) polarized glasses method
It uses two film cameras placed side by side to represent the left and right eyes of the person, and simultaneously shoots two film images with slightly horizontal parallax.
When the audience wears special polarized glasses, the left eye can only see the left image and the right eye can only see the right image. The left and right images are superimposed on the retina through the binocular convergence function, and the brain nerve produces a three-dimensional visual effect. This 3D technology is not a true 3-dimensional technology, and its imaging is still a projection technology based on a two-dimensional plane.
(II) Holographic 3D Technology
1. Holographic principle
Holography is divided into two steps: interferometric recording of the wavefront and diffractive reconstruction of the wavefront. Taking Fresnel holography as an example, the first is the interference recording of the wave front, as shown in Figure 1, which is the recording optical path of Fresnel holography.
As shown in the figure, the laser beam is divided into two beams through the beam splitter plate after passing through the shutter: the transmitted beam is reflected by the plane mirror M2, expanded by the beam expander L2 and projected onto the holographic dry plate e as reference light; The reflected beam is reflected by the plane mirror M1 and expanded by the beam expander L1, then shines on the subject, and is also projected on e as an object beam after diffuse reflection by the object. The optical axis of the whole optical path is on the same horizontal plane, and the light beam passes through the center of each element. The angle between the object light and the reference light is about 45 °.


The above article is reproduced from the Internet, copyright owned by the original creator. If there is any source labeling error or infringement, please contact us and we will deal with it in time.


keyword: