From: quest@iowegia.uucp (Steve J. Quest)
Newsgroups: sci.physics
Subject: Re: Need Help for Laser Science project
Date: 5 Sep 92 23:00:55 GMT
Organization: Iowegia Public Access Usenet/UUCP, Clive IA USA.

campbell@ctcvax.ccf.swri.edu writes:

> Hello, I am Steven Campbell a 13 year old boy with a He-Ne 1.7mW laser. 
> Also, I would like to learn more about the power of this laser. For 
> example is this the kind of laser that will give people cateracts 
> if they look at this laser from a distance. 
> 

Steve,

        You and I have the same first name!  Hello, and welcome to 
the world of science!  I work in science education and should be 
able to help you out.  Take note of my email address should you 
want to correspond in private on this subject.  My address is 
quest@iowegia.uucp

        Lasers are a lot of fun, but for safety you should never 
be careless with them.  The laser you have is capable of burning 
the cones and rods off of your retina (in your eye) leaving you 
with blank spots in your vision.  I work with an 8000mw laser 
every day and take special precautions- as it not only is capable 
of severe eye damage, it is capable of burning flesh (or anything 
else that can absorb light and become hot).  You must *never* 
stare down the beam of your laser!  If however you should get a 
glance down the beam- quickly blink and pull your head out of the 
path.  I have taken a full watt (1000mw) this way with no damage 
to my eye.

        When you ask "what science project can you do with a laser 
such as this", you are asking a question with MANY answers.  What 
would you LIKE to do?  Does the idea of 3D photography interest 
you?  You can use that laser and a simple optic (microscope 
objective) to produce what are called "white light" holographs.  
Using simple reflection holograph technology you can produce 
striking 3D photographs of reflective objects (metal objects with 
detail work best).  How about a demonstration of persistance of 
vision?  Have you ever seen a laser show?  The images you see are 
drawn with just one dot that moves very quickly and tricks the eye 
into believing it is made up of solid lines.  To do this you will 
need to build x and y deflection mirrors- which I can detail for 
you if you are interested.  They are simple to make and you don't 
*need* to use first surface mirrors.  How about lightwave 
communications?  Laser beams can be modulated (varied in intensity 
or pulse width) and this modulation can carry information, such as 
your voice.  You can then send this modulated laser down a glass 
fiber and demonstrate how fiberoptic communications work.

        You can also fire the laser through various optical 
devices such as defraction gratings (this is really neat) and 
lenses to expand or columate (condense) the beam and make the beam 
more intense.  To make the beam visible, you can either use smoke 
or water vapor (try a spray bottle in the beam path).

        I know I have left out a lot of really neat things, but 
these were the simple ones I could think of.  There are other 
simple projects which I haven't thought of and hopefully some 
others here will mention them...................sq

(please feel free to write me if you have any questions!)


Steve J. Quest            quest@iowegia.uucp
Newsgroups: sci.physics