Laser Safety Officer QUESTIONS &
ANSWERS(RATED A+)
Radiant Energy - ANSWER Energy that is emitted, transferred or received. Measured in
Joules
Radiant Power - ANSWER Power emitted, transferred, or received in the form of
radiation. Measured in Watts
Irradiance - ANSWER Radiant power striking a surface divided by the area it is striking
W/cm2
Radiant Exposure - ANSWER Exposure over a particular area divided by the area it is
striking W/cm2
What does Laser stand for? - ANSWER Light Amplification by Stimulated Emission of
Radiation
What does a laser consist of? - ANSWER A Pumping System - What imparts energy to
the atoms of the lasing medium
An Optical Cavity - Contains the medium, has mirrors and provides
amplification/selection of photons
Laser medium - Can be solid state (ND:YAG), gaseous (HeNe, CO2, Ar,Kr), dye lasers
(Rhodamine 6G), and semiconductor
What are the four modes of laser operation? - ANSWER Continuous Wave - Beam time
over 0.25s
Single Pulsed -
Single Pulsed Q-switched - stored to increase power before release
Repetitively pulsed - Pulsed repetitively
The different time modes provide different rates at which energy is delivered
What are three characteristics of a laser beam - ANSWER They are single wavelength
(monochromatic) that are tightly in phase with each other (coherent), and they are
tightly focused (collimated)
What are the two main US Government agencies involved in laser regulation? -
ANSWER OSHA and FDA
What AFI covers the Laser Radiation protection program - ANSWER AFI 48-139, we
also use ANSI 136.1
What constitutes a class 1 laser? - ANSWER Cannot emit laser radiation capable of
causing eye/skin injury.
, A 1M is similar, but can cause damage if passed through magnifying optics.
These may be a higher class during maintenance/service
What constitutes a class 2 laser? - ANSWER 2 - Staring into beam is an eye hazard.
CW max 1mW
2M - Potentially hazardous if collecting optics are used;
CW max 500mW
These lasers are in the visible light spectrum 400-700nm
What constitutes a class 3 laser? - ANSWER 3R - Marginally unsafe for direct and
specular viewing.
CW max 5mW
3B - Unsafe for direct and specular viewing. Usually not unsafe for diffuse viewing. CW
max = 500mW
What constitutes a class 4 laser? - ANSWER Exposure to direct and scattered beam
can cause eye/skin damage. Continuous wave power >0.5W. It is a fire hazard
What is an Excimer Laser? - ANSWER Excited Dimer. It is operated using a reactive
gas that is put into an excited state
What are some characteristics for common gas lasers? - ANSWER HeNe - 633nm
wavelength. Used in many consumer products
Ar,Kr,Xe - 322-799nm wavelengths. Ar has the highest visible power levels. Stable high
output up to 20W.
CO2 - Most efficient (10%-30% efficient) and powerful CW lasers. >30W at Far-IR.
What are some characteristics for solid state lasers - ANSWER Generally an active
medium of crystal doped with an impure ion. Can have very high outputs (2000W)
Semiconductor diode laser - ANSWER Used in many applications to include
spectroscopy, communication, scanners, etc. Most common is a gallium-arsenide
junction which emits a fan shaped beam at 840 nm.
Dye Lasers - ANSWER The medium is a dye. Emits UV to near IR-Spectrum range of
beams. These are tunable lasers.
What are the common hazards in regards to laser usage? - ANSWER The most
common hazard is from the beam. The most common injuries are eye and skin damage
due to thermal effects. Class 4 laser systems can also place things on fire.
What are common non-beam laser hazards? - ANSWER IH - Compressed gases/ toxic
materials and noise.
Explosion Hazards -
Non-beam Optical Hazards - UV radiation
Enclosure flammability
ANSWERS(RATED A+)
Radiant Energy - ANSWER Energy that is emitted, transferred or received. Measured in
Joules
Radiant Power - ANSWER Power emitted, transferred, or received in the form of
radiation. Measured in Watts
Irradiance - ANSWER Radiant power striking a surface divided by the area it is striking
W/cm2
Radiant Exposure - ANSWER Exposure over a particular area divided by the area it is
striking W/cm2
What does Laser stand for? - ANSWER Light Amplification by Stimulated Emission of
Radiation
What does a laser consist of? - ANSWER A Pumping System - What imparts energy to
the atoms of the lasing medium
An Optical Cavity - Contains the medium, has mirrors and provides
amplification/selection of photons
Laser medium - Can be solid state (ND:YAG), gaseous (HeNe, CO2, Ar,Kr), dye lasers
(Rhodamine 6G), and semiconductor
What are the four modes of laser operation? - ANSWER Continuous Wave - Beam time
over 0.25s
Single Pulsed -
Single Pulsed Q-switched - stored to increase power before release
Repetitively pulsed - Pulsed repetitively
The different time modes provide different rates at which energy is delivered
What are three characteristics of a laser beam - ANSWER They are single wavelength
(monochromatic) that are tightly in phase with each other (coherent), and they are
tightly focused (collimated)
What are the two main US Government agencies involved in laser regulation? -
ANSWER OSHA and FDA
What AFI covers the Laser Radiation protection program - ANSWER AFI 48-139, we
also use ANSI 136.1
What constitutes a class 1 laser? - ANSWER Cannot emit laser radiation capable of
causing eye/skin injury.
, A 1M is similar, but can cause damage if passed through magnifying optics.
These may be a higher class during maintenance/service
What constitutes a class 2 laser? - ANSWER 2 - Staring into beam is an eye hazard.
CW max 1mW
2M - Potentially hazardous if collecting optics are used;
CW max 500mW
These lasers are in the visible light spectrum 400-700nm
What constitutes a class 3 laser? - ANSWER 3R - Marginally unsafe for direct and
specular viewing.
CW max 5mW
3B - Unsafe for direct and specular viewing. Usually not unsafe for diffuse viewing. CW
max = 500mW
What constitutes a class 4 laser? - ANSWER Exposure to direct and scattered beam
can cause eye/skin damage. Continuous wave power >0.5W. It is a fire hazard
What is an Excimer Laser? - ANSWER Excited Dimer. It is operated using a reactive
gas that is put into an excited state
What are some characteristics for common gas lasers? - ANSWER HeNe - 633nm
wavelength. Used in many consumer products
Ar,Kr,Xe - 322-799nm wavelengths. Ar has the highest visible power levels. Stable high
output up to 20W.
CO2 - Most efficient (10%-30% efficient) and powerful CW lasers. >30W at Far-IR.
What are some characteristics for solid state lasers - ANSWER Generally an active
medium of crystal doped with an impure ion. Can have very high outputs (2000W)
Semiconductor diode laser - ANSWER Used in many applications to include
spectroscopy, communication, scanners, etc. Most common is a gallium-arsenide
junction which emits a fan shaped beam at 840 nm.
Dye Lasers - ANSWER The medium is a dye. Emits UV to near IR-Spectrum range of
beams. These are tunable lasers.
What are the common hazards in regards to laser usage? - ANSWER The most
common hazard is from the beam. The most common injuries are eye and skin damage
due to thermal effects. Class 4 laser systems can also place things on fire.
What are common non-beam laser hazards? - ANSWER IH - Compressed gases/ toxic
materials and noise.
Explosion Hazards -
Non-beam Optical Hazards - UV radiation
Enclosure flammability
