1. Holography

2. Irradiance  A photograph records the irradiance of an image. Energy per unit areaEnergy per unit area  Light areas represent high irradiance points in the object. Photo by Jason Bruges Studio

3. Amplitude Record  Image display returns the irradiance at each point. Indirectly amplitude Color photographs sort waves by frequency

4. Phase Information  Waves can be described by amplitude and phase. Amplitude alones lacks informationAmplitude alones lacks information  If phase information is included then there is everything the eye sees of the object. Three-dimensional imageThree-dimensional image Proposed in 1948, Nobel Prize in 1971.Proposed in 1948, Nobel Prize in 1971.

5. Reference Wave  To preserve phase information a reference wave is needed.  A coherent monochromatic wave maintains the same amplitude and phase on reflection.

6. Object Wave  A reflected wave from an object interferes with the reference wave. Same initial source  This interference pattern has information about phase, too. reference wave object wave

7. Transmission Hologram  The angles of the diffraction rings are used to determine the crystal spacing. holographic image

8. Hologram Viewing  Shining the same coherent light through the recorded pattern recreates a virtual image. Wikipedia Commons

9. Rainbow Hologram  An object illuminated through a narrow horizontal slit will provide partial information. Narrow horizontal sliceNarrow horizontal slice  Different slices respond to different frequencies. Based on angleBased on angle White light illuminationWhite light illumination