Holography is a technique that uses the properties of light interference and diffraction to record three-dimensional information of an object. The document discusses the history and principles of holography, how holograms are constructed and reconstructed, different types of holograms and their applications in microscopy, interferometry and more. Holography allows the recording and reconstruction of three-dimensional images from a two-dimensional surface, providing depth perception and parallax.

1. HOLOGRAPHY FROM : MUKUL TRIPATHI B.TECH FINAL YEAR (ECE) 06ESBEC049

2. index History of holography Conventional photography Holographic photography Principles of holography Hologram Hologram construction Hologram reconstruction Types of hologram Application of hologram Conclusion references

3. History of Holography Invented in 1948 by Dennis Gabor for use in electron microscopy, before the invention of the lASER Leith and Upatnieks (1962) applied laser light to holography and introduced an important off-axis technique

5. Photograph lacks depth perception or parallax

6. Film sensitive only to radiant energy

8. To view a hologram, the wavefront is reconstructed

9. View what we would have seen if present at the original scene through the window defined by the hologram

12. Interfere wavefront of light from a scene with a reference wave

13. The hologram is a complex interference pattern of microscopically spaced fringes

14. “holos” – Greek for whole message

15. Hologram construction When developed the photographic plate will have a transmittance which depends on the intensity distribution in the recorded plate tb – backgrond transmittance due to |R|2 term B – parameter which is a function of the recording an developing process

16. Hologram reconstruction Direct wave – identical to reference wave (propagates along z) except for an overall change in amplitude Object wave – Spherical wave except for a change in intensity B|r|2 i.e. reconstructed wavefront Conjugate wave – spherical wave collapsing to a point at a distance z to the right of the hologram 1 : a real image 2 : displaced by a phase angle 2kz

17. Types of hologram Transmission hologram Reflection hologram Holographic Stereograms Rainbow hologram Colour holograms Lens hologram Fourier hologram

18. Transmission hologram reference and object waves traverse the film from the same side

19. Reflection hologram reference and object waves traverse the emulsion from opposite sides

22. 3 holograms + 3 wavelengths: larger gamut

23. Achromatic holograms: holographic stereograms1 : Overlapping/coplanar colors

25. Use of thin lens: assumption on lack of diffraction

27. F{planar image} + F{point source}

28. Reconstruction through lens

30. conclusion Holography is the only visual recording and playback process that can record our three-dimensional world on a two-dimensional recording medium and playback the original object or scene to the unaided eyes as a three dimensional image. The image demonstrates complete parallax and depth-of-field and floats in space either behind, in front of, or straddling the recording medium.

31. references BOOKS REFERED 1 : Barrekette’s application of holography 2 : Ostrovsky’s holography Noble lecture by DENIS GABOR on his holographic module www.google.com

32. QUERY ?