From: '''newspam'''@nonad.co.uk   
      
   On 06/12/2025 22:16, Joe Gwinn wrote:   
   > On Sat, 06 Dec 2025 14:00:16 -0800, john larkin    
   > wrote:   
   >   
   >> On Sat, 6 Dec 2025 13:06:18 -0800, wmartin  wrote:   
   >>   
   >>> Greetings,   
   >>> Just musing here. How might I couple a fiber optic cable to the optical   
   >>> window on a Lidar chip? Wondering if it's possible to do Lidar through a   
   >>> twisty path, like routed around an arbitrary light blocking "thing". Are   
   >>> there going to be intractable reflections at one or both ends of the   
   >>> fiber? I do have a use for this if it is possible...   
   >>> Regards,   
   >>> Bill M.   
   >>   
   >> If the lidar chip has a window, and the beam is expanded to some   
   >> modest diameter, you'd need a lens to get any amount of useful   
   >> coupling.   
   >>   
   >> Got a link to the part?   
   >>   
   >> There are lots of cheap OTDRs around, so there must be   
   >> fiber-compatible parts.   
   >>   
   >   
   > There are.  What are used for coupling are ball lenses or GRIN lenses.   
   >   
   > Aligning these things by hand is possible, but very fiddly, so most   
   > folk buy a pigtailed laser as the optical pulse source.  The LIDAR   
   > chip drives the source and listens to the receiver (also pigtailed).   
   > And so on.   
      
   I have seen a variant that I thought was a very creative use of this   
   Lidar technology in kitchen design. A friend in the glass cutting   
   business (think laser cut bespoke kitchen splashbacks) has a black box   
   gizmo with a reeled fibre optic sensor probe. You put the probe onto the   
   wall and get back an x,y,z position relative to a central datum.   
      
   Take it home run some clever software and it generates the exact CNC   
   cutting profile for their laser cutter and just press go.   
      
   Compared to hand measurement it is incredibly quick and absolutely spot   
   on to mm accuracy so there is no fiddling about to fit it later. It also   
   spots walls that are bowed in some way or not truly flat and works out   
   the most reasonable compromise fixup solution to adjust it to be so.   
      
   He's very pleased with it. Complex installations with lots of cutouts   
   that used to take all day and with a slight risk of damaging the piece   
   of glass doing manual final adjustments now take a couple of hours.   
      
   --   
   Martin Brown   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)