On 3/9/07 6:32 AM, in article meeIh.12816$4D.3099@pd7urf2no, "Robert"
<rjshaw7@hotmail.com> wrote:

I know more about lasers than urology. A holmium (Ho) laser emits in the
infrared at a wavelength of about 2.1µm. This is, of course, invisible and
less likely to cause accidental eye damage. It works because all tissue
(meat) is mostly water. It is the water that gets heated up and cooked.

I am guessing that the green "laser" is a neodymium (Nd) laser operating in
the infrared at about 1.06µm which is then frequency doubled to 0.53µm which
is green. It will get absorbed by almost anything that is red. Blood and
meat are examples. Because of the shorter wavelength, the beam can be made
finer for more precise "carving."

I am guessing that both lasers are Q-sitched. That means that instead of
being continuous in time, the beam power is concentrated into short pulses.
It is these short pulses that cause almost instantaneous evaporation when it
gets absorbed at a surface. Again, I am guessing, that for the same AVERAGE
beam power the shorter pulse help ablate the surface instead of merely
cooking it.

Bill
-- Fermez le Bush--about two years to go.

only if they have been properly trained and have done many
procedures.  Salmon is right about the wavelenghts.  The green
wavelength is better suited to blood and will coagulate better.
Tissue vaporization should be more efficient too because the Holmium
wavelenght loses energy as it transmits through the saline environment
whereas the green wavelength goes right through to the tissue
surface.  However, as I said in the first sentence, experience and
proper technique are important.  And definitely stay away from Holep.
Good luck.

Stay away from all laser treatments -unless you want to enjoy prostate
cancer !