A4 Off-Axis Holography

The Development of Practical Holography

The general principles of holography were known by 1950, but the extreme difficulty of producing and reading out holograms with the light sources of that time left holography as a laboratory curiosity until the advent of the laser in the 1960’s. Even then the technique remained of little real use until 1962 when Michigan scientists Emmett Leith and Juris Upatneiks introduced their method of off-axis construction/reconstruction. Their method became a standard approach to image reconstruction in modern holography.

The University of Michigan College of Engineering supported the construction and installation in 2013  of a 15’x 9’x 5′ commemorative sculpture  that is now on the plaza of the Engineering Research Building on the North Campus:

2 7667BW-Holog-InstallLongView(2)I began with small maquettes:4172AW_paperHolography copyand a proposal:7773W_HolographyEngResBldgbut I wanted to explore the moiré effect in which, in analogy to holography, the superposition of two periodic structures yields a third pattern that depends on the position of the observer.  A small construction made of bamboo skewers showed some promise:5942AR_HolographyRodPropThen a larger scale maquette made of the same PVC pipe that one uses for home plumbing:6078-80C-_HolographyPVCThen proceeding to construction at full scale with stainless steel:5781-DaveCarterOffAxisHolog-Boring-Sept2012and assembly:7655_Holog-AssembleFirstElementeverything in place:7684AW-Holog-JCZ-Carterfor the final result in September of 2013:Off-Axis Holography

 

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Exploration of Moiré Alternatives

Assemblies of perforated metal can present interesting patterns that shift dramatically as the observer moves: 6259-MoireSculpture

 

So Josh Blackmon and I built a contoured column, 44″ high, from 3/8″ perforated stainless steel, that gives a good demonstration of Moiré:
00079-83-84-85B-HologMiniMoire

 

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Another approach

This possibility for celebrating holography derives from the Radar sculpture.  (To me this conveys some aspects of sailing ; it might be considered for a yachting trophy.)

3817AW2_HolographyWaveInter