______________________________________________________________________________
|  File Name      : PLASTLAS.ASC     |  Online Date     :  03/10/95          |
|  Contributed by : Bert Pool        |  Dir Category    :  ENERGY            |
|  From           : KeelyNet BBS     |  DataLine        :  (214) 324-3501    |
|           KeelyNet * PO BOX 870716 * Mesquite, Texas * USA * 75187         |
|        A FREE Alternative Sciences BBS sponsored by Vanguard Sciences      |
|----------------------------------------------------------------------------|
Source: R&D Magazine

              Solid Plastic Laser Rods May Replace Lasing Liquid

Liquid dye-based lasers have some capabilities that just cannot be substituted
by using solid, semiconductor, or gas lasers.  But there are considerable
engineering obstacles to surmount when designing a dye laser.  These obstacles
add greatly in cost of the instrument.  They include such things as liquid
circulating pumps, coolant systems, large reservoirs of spare lasing dye, and
delicate optical systems external to the dye cell - itself a delicate and
complex piece of apparatus.

So all in all, a dye laser is a bulky, complicated, expensive, and difficult-
to-service device.  Another drawback is many of the solvents used to dissolve
the dyes are poisonous, and present not only a personal hazard, but an
environmental disposal problem.

A new and exciting development may change all that.  A research team under the
direction of polymer scientist Robert Hermes at Los Alamos National Laboratory
in New Mexico has developed PLASTIC dye laser rods, where the lasing dye is
contained in a two-polymer plastic called hydroxypropyl acrylate with methyl
methacrylate.  Thus, all the bulky, delicate systems of dye lasers could be
replaced simply by slipping the appropriate emission wavelength plastic laser
rod in the optical cavity next to the laser pumping flash lamp.

The new, patented plastic was developed as a weapon - for use in flashblinding
gangs, terrorists, hostage takers, or perpetrators of riots.  The
flashblindness would be only temporary, but would suffice to stop the
lawbreaker cold.

Weaponry isn't the only area where plastic laser rods will prove useful.  Any
application where a low-power laser could be used that needed almost instant
tunability of wavelength would greatly benefit.  For instance, in the medical
field, wavelength changes of a few nanometers could be accomplished by
adjusting the optical cavity - a simple mechanical procedure.

Larger wavelength changes could be done by inserting a laser rod of the
appropriate color into the optical cavity.  It wouldn't require trained
personnel to go through the procedure of changing the liquid dye in the lasing
cell.  This would be a boon to operating room personnel, as several light
stimulated procedures could be performed in one session, rather than in
subsequent sessions.

Example procedures include photodynamic therapy for cancer, a combination
technique using a photoactivated drug and a laser to destroy tumors, and
various optical biopsy and surgical techniques.
------------------------------------------------------------------------------

   The new plastic rod dye lasers will be great when they finally become
   available - if we can afford them.  KeelyNet researchers might be better
   off getting a copy of the patent, and making their own dye-containing
   plastic rods.  The basic precursors for mixing different plastics are
   available, and I suspect that with some experimentation an individual
   could eventually replicate these rods.
                                                           >> Bert
------------------------------------------------------------------------------