[HN Gopher] Corkscrew Optics Yield Direct Line to Electronics
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       Corkscrew Optics Yield Direct Line to Electronics
        
       Author : mfiguiere
       Score  : 62 points
       Date   : 2022-12-16 22:49 UTC (2 days ago)
        
 (HTM) web link (spectrum.ieee.org)
 (TXT) w3m dump (spectrum.ieee.org)
        
       | naturedivine wrote:
       | Perhaps we can use fewer optical gates and serialize the use of
       | gates, using pipelining at gate level.
        
       | arc-in-space wrote:
       | Actual paper: https://www.science.org/doi/10.1126/sciadv.abq8246
        
       | perihelions wrote:
       | - _" The new gates performed at speeds of less than 100
       | femtoseconds, which is roughly 1 million times as fast as
       | electronic gates_"
       | 
       | Electronic gates switching at 10 MHz?
        
         | oh_my_goodness wrote:
         | Yeah, they're off by a factor of 1000.
         | 
         | There are other serious technical errors in the piece too. For
         | example they say "because photons move at the speed of light
         | and electrons don't" ... which is irrelevant because electronic
         | signals do move at the speed of light.
         | 
         | The most serious problem is missing context. It's been known
         | for decades that you can build shockingly fast optical switches
         | and even amplifiers. A hundred fs is fast but not unique. The
         | problem is how to connect these devices in a complicated
         | circuit without putting nanoseconds of waveguide in between.
         | Unfortunately 1 ns is 1,000,000 fs.
         | 
         | So in telecom, where you're just going a long way in one
         | direction, optical amplifiers with multi-THz bandwidth have
         | dominated transport since the 1990s. But in computers, no.
        
           | blep_ wrote:
           | Electronic signals also do not move at the speed of light:
           | https://en.wikipedia.org/wiki/Velocity_factor
        
             | teddyh wrote:
             | Yes they do. It's just that the speed of light differs
             | slightly depending on the medium.
        
               | ilyt wrote:
               | No, you can have different speed in same copper material.
               | 
               | At least read the fucking link they provided instead of
               | saying bollocks...
        
         | amelius wrote:
         | 1 femtosecond = 1e-15 seconds.
        
           | perihelions wrote:
           | Right, so 100 fs = 1e-13 seconds. And a million times slower
           | than that would be 1e-7 seconds, or (10 MHz)^{-1}.
        
             | greenbit wrote:
             | Commodity PCs were running 10MHz clocks by 1988, weren't
             | they?
        
               | tiagod wrote:
               | The point is they now run at several GHz, so their
               | comparison is off by orders of magnitude.
        
         | photochemsyn wrote:
         | Probably just a miscommunication. The actual improvement is
         | more like 10K times, but this moves from the 'gigahertz range'
         | to the 'petahertz range' which differ by 1e6.
         | 
         | > "Since light oscillates so fast (roughly a few hundred
         | million times per second), using light could speed up
         | electronics by a factor of roughly 10 000 as compared to
         | computer chips," says Tobias Boolakee, a laser physicist in
         | Peter Hommelhoff's group at the FAU and the first author of a
         | study in Nature on the new gate." (2022)
         | 
         | https://physicsworld.com/a/logic-gate-breaks-speed-record/
        
           | oh_my_goodness wrote:
           | Light oscillates much, much faster than a few hundred million
           | times per second. Take 1 micron wavelength. At a speed of 3e8
           | m/s, 1 micron light oscillates 3e8/1e-6 = 3e14 times per
           | second. Three times ten to the fourteenth power.
           | 
           | For anybody who doesn't juggle large numbers every day, a
           | hundred million is 1e8. Ten to the eighth.
        
             | photochemsyn wrote:
             | Maybe they meant trillions? The 10,000 times faster number
             | seems correct though, as fiber optic carries light at
             | ~200-300 THz and 10 GHz is the electronic standard at
             | present.
        
         | tiagod wrote:
         | I remember this exact issue in the last HN front-page article
         | about optical gates, weeks ago...
        
           | airstrike wrote:
           | Do you have a link? Would love to read that
        
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