T-45C TS, ADV & IUT ENG-24
GINA Operating Characteristics
Light Amplification by Stimulated Emission of Radiation
(LASER) beam generation is used for many applications.
Some products are very high-energy beams employed in
manufacturing to cut metals. Others, like those in ring laser
gyros, are used for applications that require less power.
The process of creating a gas laser beam, such as is used in a
ring laser gyro, is begun by the application of electrical power to
a gas that forms a plasma. The process entails ionization of a
contained gas. That is accomplished by energizing an
electrical current between an anode (+) and cathode (-) that are
immersed in the contained gas. Ionization is the effect of
creating a charge on the gass molecules by causing some
electrons to occupy a higher energy state [different orbits].
Large numbers of electrons are moved to higher, but unstable,
energy states in a plasma.
The actual laser beam forms, when free electrons in a plasma
return to a stable position/condition in molecular orbit. At that
moment, energy is released in the form of light; photons are
generated. The photon emission rate is linked to the degree of
power applied to the laser tube and contained gas; more
power/more laser light from more photons.
The emitted laser light is all in the same frequency, which is
related to the type molecules/atoms being lased. Hence, it is
termed a coherent light. Next, that coherent light is polarized
and redirected with mirrors.
In high-energy lasers, a great deal more power is applied to the
laser and the light beam is amplified by repeated reverse
reflections. Actual designs of lasers vary, considerably. Some
use gas, others like ruby lasers, use crystals.