2. WHAT IS A LASER?
A Laser is a device that produces a narrow beam of coherent
light. The word laser comes from a phrase that describes how
it works: light amplification by stimulated emission of
radiation. Light amplification means that the light is
strengthened. Stimulated emission means that the atoms
emit light when exposed to electromagnetic radiation.

3. HOW CAN LASER LIGHT BE USED
Laser
can be
used for
hair not
to grow

4. HOW DOES A LASER
PRODUCE LASER LIGHT?
•A helium-neon laser is shown at the bottom of the slide.
•The laser tube contains a mixture of helium and neon gases.
•An electric current causes this gas mixture to emit photons.
•You may recall that a photon is a packet of light energy.
•The mirrors at both ends of the tube reflect the photons back and forth.
• As a photon travels back and forth, it may bump into a neon particle. This causes the neon
particle to emit a photon with the same energy as the one that caused the collision.
•Then the two photons travel together in step with one another.
•This process continues until there is a stream of in-step photons traveling up and down the
tube.
•Some of the light “leaks” through the partially reflecting mirror.
•This light is the laser beam.

5. HOW IS LASER LIGHT DIFFERENT AND STRONGER THAN
REGULAR WHITE LIGHT?
Laser light is very coherent. This means that the waves
leaving the laser remain in phase for a very long time. Light
from a flashlight is not coherent. As a result, a laser can
project a distinct beam of light much farther than a
flashlight.
Laser light is almost monochromatic. Because it is created by
exciting a specific substance to emit photons, the light emitted
by the source is almost all one specific wavelength. The light
from a flashlight contains all of the colors in the spectrum,
Laser light is directional. This means that the
forming "white light".
beam of light being emitted does not spread
much with distance. Hence it can still appear
as a point of light many meters away from
the source. A flashlight beam will quickly
spread the further it is viewed from the
source.

7. IS LASER LIGHT DANGEROUS
•A laser is "concentrated light" in that its light of pretty much one
frequency and focused in a tight beam.
•And if this light is directed into someone's eyes, damage to the retina can
result.
•In higher power lasers, we find applications where they can inscribe
diamonds or cut all kinds of things, including metal.
• If a laser beam can cut through a thick metal plate, it can cut through
flesh with ease.
•A laser this powerful could take off a limb.
•Directed at the eye, it would destroy the eye in an instant.
•Spaces where lasers are being used require that warning signs be posted
and that individuals working there wear appropriate eye protection.
•Divergence from safety procedures can result in serious injury.

8. HOW CAN WE PROTECT OUR EYES FROM LASER
LIGHT?
•wearing laser safety glasses or goggles can protect the eyes from the risks that lasers pose.
•These laser safety glasses and goggles provide protection from reflected laser light and direct beam
exposure.
•It is recommended that you find out the class of the laser you are working with as well as the appropriate
wavelength range to ensure the best possible protection.
•We can’t emphasize enough how important it is to protect your eyes and yourself from the harmful effects
of laser radiation.
•Remember, the damage done to the eyes from laser radiation exposure can be permanent!