[Laser] Tutorial.

[Joe Fitzgerald [ jfitzgerald@alum.wpi.edu ]]

See http://laserinstitute.org/safety_bulletin/laser_safety_info/ for a
formal tutorial.

The primary hazard at 10W or less is to your vision.  When you set up your
test arrangement, have your beam path below eye level.  And yes, you should
have an absorptive load see
http://www.kentek-laser.com/accessor/beamdump.htm  for an idea of how one is
built.  Key design features are the grazing angle at which the beam hits the
absorbtive surface directing secondary reflections deeper into the unit, and
the black color.  The conical structure is nice, but if you don't want to
shell out $200, consider two  flat black surfaces in a steep "V"
configuration.  Your idea of bricks sounds OK - try to find dark ones.  The
laser probably won't touch the tin foil ... I know a 10W Nd:YAG laser at
1064nm won't touch it.  All the laser energy just scatters away.  You can
ignite paper, but colored paper absorbs more energy than white.  A photocopy
of a dark object (or just press "copy" with the cover open), makes a nice
laser target - the toner absorbs most of the incident laser energy, and
leaves a good mark.  Ten watts will burn right through.


-Joe KM1P