Re: [CAD_CAM_EDM_DRO] re: DRO computer

> I don't suppose you have any references for this kind of system do you?

http://www.misty.com/~don/lasersam.html

FAQ on lasers. The best FAQ I've seen
in years.

http://www.repairfaq.org/sam/laserdio.htm#diotoc

Diode laser FAQ subsection

http://www.repairfaq.org/sam/laserlia.htm#liaint4

"Interferometers Using Inexpensive
Laser Diodes", new section since I read
the FAQ (conclusion: maybe)

www.zygo.com High-end interferometry

www.lasermax-inc.com Nano-Trak cheaper interferometry ($6K Jan '99)

www.optodyne.com Laser Doppler Scale

www.powertechnology.com Laser diodes of every description

www.edisci.com Cheaper optical components

> 3 wire connection but only two used

The third lead is for a photodiode to monitor laser power output.

> and a small plastic convex lens (why is this needed?)

The light comes out of the diode in a squashed cone shape (elliptical
cross section), but the laser pointer wants it parallel.

> Connection to the laser diode is direct from the 3 mercury batteries
> via a simple push button switch and so I assume that the diode
> incorporates current control within itself.

I believe that's outboard circuitry, and it's fairly exotic. Less
exotic now that they've put a zillion copies of it into keychains, but
not something you can trivially whip up. Laser diodes are very
sensitive to electrical glitches, and they only work when run close to
destruction. The powerup transient must be rigidly controlled.


A member of the League for Programming Freedom (LPF) http://lpf.ai.mit.edu
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