[HN Gopher] Computer-generated holography with ordinary display
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       Computer-generated holography with ordinary display
        
       Author : ta988
       Score  : 110 points
       Date   : 2024-04-15 01:37 UTC (21 hours ago)
        
 (HTM) web link (opg.optica.org)
 (TXT) w3m dump (opg.optica.org)
        
       | schappim wrote:
       | The paper:
       | https://preprints.opticaopen.org/articles/preprint/Computer-...
        
       | westurner wrote:
       | CGH: Computer-generated holography:
       | https://en.wikipedia.org/wiki/Computer-generated_holography
        
       | btbuildem wrote:
       | > We demonstrate three-dimensional color image reproduction using
       | a two-layered hologram cascade composed of an iPhone and a
       | spatial light modulator.
       | 
       | So, not just an ordinary display then? What does this "spatial
       | light modulator" look like?
        
         | toast0 wrote:
         | In this application, it would probably look like a transparent
         | liquid crystal display on top of the phone. Usually LCDs are
         | modulating the polarity of light, and you have polarizing
         | filters before and after so that the modulation of polarity
         | results in modulation of intensity; but I've read about other
         | ways to arrange the LCD such that you modulate the phase of the
         | light passing through instead, that's what you need for
         | holography (although I thought you needed a coherent light
         | source)
         | 
         | Here's a commercially available SLM based on reflective Liquid
         | Crystal on Silicon (similar to what you might find in an LCD
         | projector), that actually has listed prices:
         | https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=10...
         | No endorsement, just an early search result.
        
         | Animats wrote:
         | Probably like this.[1]
         | 
         | It's a variant on a liquid crystal display, set up to adjust
         | phase, rather than intensity. Clever. Price around US$13,000
         | and up.
         | 
         | [1]
         | https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=10...
        
           | hellonull wrote:
           | That is lab equipment, of course it's going to be
           | horrendously expensively. Look how much a pack of bolts
           | costs.
        
             | amelius wrote:
             | Yes, but you get lab snacks :)
        
       | boboche wrote:
       | An actual holographic article, not some autostereoscopic or
       | barrier! Thanks for the find!
        
         | BlueTemplar wrote:
         | For your bookmarks :
         | https://www.youtube.com/watch?v=TsyzTUa-3VE
        
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       (page generated 2024-04-15 23:02 UTC)