This document discusses different types of lasers, their uses, and laser safety. It describes excimer lasers, dye lasers, and semiconductor lasers. It outlines laser uses in medicine, industry, and everyday life. It also discusses non-beam hazards, laser classifications and labeling, control measures like engineering controls and PPE, and signs used for laser safety.

10. • Excimer lasers (the name is derived from the
terms excited and dimers) use reactive gases such as chlorine and
fluorine mixed with inert gases such as argon, krypton, or xenon. When
electrically stimulated, a pseudomolecule or dimer is produced and
when lased, produces light in the ultraviolet range.
• Dye lasers use complex organic dyes like rhodamine 6G in liquid
solution or suspension as lasing media. They are tunable over a
broad range of wavelengths.
• Semiconductor lasers, sometimes called diode lasers, are
not solid-state lasers. These electronic devices are generally very
small and use low power. They may be built into larger arrays, e.g.,
the writing source in some laser printers or compact disk players.

11. Lasers are also characterized by the duration of
laser emission - continuous wave or pulsed laser.

12.  In medicine
 to break up gallstones and kidney stones,
 to weld broken tissue (e.g. detached retina)
 to destroy cancerous and precancerous cells; at the same
time, the heat seal off capillaries,
 to remove plaque clogging human arteries.
 Surgical treatment

13.  In industry
 to drill tiny holes
in hard materials,
 for welding and machining,
 for lining up equipment precisely,
especially in inaccessible places.

15.  In everyday life
 to be used as bar-code readers,
 to be used in compact disc players,
 to produce short pulses of light
used in digital communications,
 to produce holograms.

16.  Holography is the production of
holograms by the use of laser.
 A hologram is a 3D image
recorded in a special
photographic plate.
 The image appears to float in
space and to move when the
viewer moves.

17. In a fraction of a
second, your vision
can go dark.

18. NON-BEAM HAZARDS
Non-beam hazards refer to anything other than the laser
itself that can create a hazard. This type of hazard
includes:
 Electrical Hazards
 Fire Hazards
 Laser Generated Air Contaminants (LGAC)
 Compressed Gases
 Noise

19.  Class 2:
“Laser Radiation – Do Not Stare into Beam.”
 Class 2M:
“Laser Radiation – Do not Stare into Beam or
View Directly with Optical Instruments.”
 Class 3R:
“Laser Radiation – Avoid Direct Eye Exposure.”
 Class 3B:
“Laser Radiation – Avoid Direct Exposure to Beam”
 Class 4:
“Laser Radiation – Avoid Eye or Skin Exposure
to Direct or Scattered Radiation.”
Only Class 1 lasers require no labels. All other lasers must be labeled at the beam’s point of
origin.

20. ” indicates a very dangerous situation that could
result in serious injury or death. This sign should be used for
Class 3R, 3B, and 4 lasers.
 “ ” indicates a potentially hazardous situation which
could cause a less serious injury. This sign should be used for
Class 2 and 2M lasers.
 “ does not indicate a hazardous situation. This sign
should only be used to make people aware of facility policies
regarding laser safety and/or to indicate that a service operation
is in progress.

21. “CAUTION” Warning Sign
CAUTION
Laser Class and system
Type of Laser, emitted
wavelength, pulse duration,
and maximum output
Safety Instructions may include:
• Eyewear Required
• Invisible laser
radiation
• Knock Before Entering
• Do Not EnterWhen Light
is On
• Restricted Area
Safety Instructions

22. “DANGER” WARNING SIGN
DANGER
Laser Class and system
Type of Laser, emitted
wavelength, pulse duration,
and maximum output
Safety Instructions may
include:
• Eyewear Required
• Invisible laser
radiation
• Knock Before Entering
• Do Not Enter When
Light is On
• Restricted Area
Safety Instructions

23. “NOTICE” Sign for Laser Repair
NOTICE
Safety Instructions
(such as “Laser Repair in
Progress”)
Laser Class and system
Type of Laser, emitted
wavelength, pulse duration,
and maximum output
Safety Instructions may
include:
• Eyewear Required
• Invisible laser
radiation
• Knock Before
Entering
• Do Not Enter When
Light is On
• Restricted Area

24. Control Measures
 There are several measures that can be taken to prevent injury from
lasers. These measures include:
 Engineering Controls:
Engineering controls are measures that are incorporated into the laser system and are designed to
prevent injury to personnel
 Administrative Controls:
Administrative controls are procedures that are designed to prevent personnel from injury
 Personnel Protective Equipment
 Warning Signs and Labels

25. Personnel Protective Equipment
 For skin :
Ultraviolet lasers and laser welding/cutting operations may
require that tightly woven fabrics be worn to protect arms and hands.
 For eyes:
Personnel Protective Equipment (PPE) for eyes
exposed to Class 3B or 4 lasers is mandatory.
Eyewear with side protection is best.