What is a laser A laser is a

What is a laser ? A laser is a device that generates light by a process called STIMULATED EMISSION. The acronym LASER stands for Light Amplification by Stimulated Emission of Radiation Semiconducting lasers are multilayer semiconductor devices that generates a coherent beam of monochromatic light by laser action. A coherent beam resulted which all of the photons are in phase.

What is a Hologram? -A Hologram is a three dimensional image -While standard photography records color and intensity information, a hologram encodes phase and intensity. -A Holographic Image is created using a coherent light source to create an interference pattern on a film or plate. -When reconstructed, an observer can view a virtual image beyond the film that contains all possible perspectives of the object that available according to the placement of the film.

LASER HOLOGRAPHY

Hologram Basics: • A laser-generated image with three-dimensional properties • Created by capturing the intensity and phase information produced by the interference of two (or more) beams of light • 2 basic types of holograms: Transmission and Reflective Object Beam Reference Beam Interference Pattern

Holography in every day life Holograms that simply redirect light may be used as inexpensive optical elements, serving in place of lenses and mirrors. To cite one popular application, laser readers of the universal product code on groceries use a spinning disc outfitted with a number of holographic lenses. By continuously providing many angles of laser scanning, the product code can be identified even when the item is passed casually over the scanner.

Holography in every day life Holographic data storage also offers tremendous potential. Because data can be reduced by the holographic technique to dimensions of the order of the wavelength of light, volume holograms can be used to record vast quantities of information. As the hologram is rotated, new exposures can be made. Photosensitive crystals, such as potassium bromide crystals with color centers or the lithium niobate crystal, can be used in place pf thick-layered photoemulsions. Because information can be reduced to such tiny dimensions and crystal can be

Holography in every day life A telephone credit card used in Europe has embossed surface holograms which carry a monetary value. When the card is inserted into the telephone, a card reader discerns the amount due and deducts (erases) the appropriate amount to cover the cost of the call. Supermarket scanners read the bar codes on merchandise for the store's computer by using a holographic lens system to direct laser light onto the product labels during checkout.

Trends and Vision Next generation displays will be 3 D Black&White Colour High Definition TV A paradigm shift in visualization The market is waiting for a real solution 3 D data is already there, but lost while displaying