laser scope

[Alexis]

On Monday 23 March 2009 16:39:20 Jim Battle wrote:
> David Griffith wrote:
> ...
>
> > Now and then I think it would be nice to have a vector monitor for
> > general fooling around.  Then I start thinking about using a laser in
> > place of an electron beam.  Hmm... Anyone have any suggestions on
> > pursuing that?
>
> I'm sure the bandwidth of the electron beam is many times greater than
> what you could achieve with a laser.

Yes, but the bandwidth of an LED laser is still pretty high. There are a few 
laser projectors on the net, but this one goes into the detail of making your 
own galvos.

http://elm-chan.org/works/vlp/report_e.html

Just slightly off topic, this is a good foundation for a mechanical television 
projector. Modulate the laser to a video source and attach the galvos to two 
synchronized sawtooth generators. For PAL, you could get away with a 5MHz 
bandwidth (about 250 vertical lines visible). 

Mind you the horizontal galvo will be screaming along at 15625Hz, which is 
pretty darn fast, faster for NTSC, and I reckon the laser would have a hard 
time keeping up. Maybe a Scophony system would be more appropriate. :)

In any case, an oscilloscope will work by far better for TV and for vector 
displays, even if the screen is smaller. They usually all have a Z axis input 
at the back.

Alexis