ACTUAL Exam Questions and CORRECT
Answers
Class 1 Laser Classification - CORRECT ANSWER - - cannot emit laser radiation at
levels that are known to cause eye or skin injury during normal operation
-very low power or beam is fully enclosed
Class 1M Laser Classification - CORRECT ANSWER - -incapable of hazardous exposure
conditions during normal ops unless viewed with collecting optics (binoculars)
-exempt from control measures, other than to prevent optical aided viewing
-exempt from other forms of surveillance
Class 2 Laser Classification - CORRECT ANSWER - -low power, emit in visible spectrum
(400-700 nm)
-not considered strong enough to damage eyes because a person will normally blink and look
away if it enters their eyes (aversion response)
Class 2M Laser Classification - CORRECT ANSWER - -potentially hazardous if viewed
with collecting optics
-upper limit on a continuous wave laser in this class is 500 mW
Class 3R Laser Classification - CORRECT ANSWER - -intermediate powered, hazardous
under direct and specular reflection viewing
-can produce no more that 5 mW in the visible region
Class 3B Laser Classification - CORRECT ANSWER - -hazarous under direct and
specular reflection viewing
-not normally a diffuse reflection or fire hazard
operate between 5-500 mW for CW systems
,cannot produce radiation energy greater than 0.125 J for pulsed systems
Class 4 Laser Classification - CORRECT ANSWER - -high power, hazardous to eye or
skin from direct beam
-may pose a diffuse reflection or fire hazard
-pose ancillary hazards including laser-generated air contaminants and hazardous plasma
radiation
Laser components - CORRECT ANSWER - -pumping system
-lasing medium
-optical cavity
Pumping System - CORRECT ANSWER - -source of power that excites the lasing
medium in order to create photons for the laser beam
-can be an electrical source, a flash lamp or another laser
Lasing Medium - CORRECT ANSWER - -what determines the wavelength of the system
-four types: solid state, gas, dye, and semiconductor
Optical Cavity - CORRECT ANSWER - -contains the lasing medium and reflective
mirrors that guide the laser beam
-provide amplification to create the desired laser parameters
LASER acronym - CORRECT ANSWER - Light
Amplification by
Stimulated
Emission of
Radiation
, Beam Characteristics - CORRECT ANSWER - -monochromatic
-coherent
-collimated
Monochromatic - CORRECT ANSWER - -light emitted by a laser is almost pure in color
of a single wavelength
Coherent - CORRECT ANSWER - -measure of the degree of phase correlation that exists
in the radiation field of a light source at different locations and different times
-waves are tightly in phase or in step with one another
Collimated - CORRECT ANSWER - -parallel (highly collimated) fashion, high degree of
a high level of directionality
Modes of Operations - CORRECT ANSWER - -continuous or pulsed
Radiant Energy (Q) - CORRECT ANSWER - -energy that is emitted, transferred, or
received in the form of radiation; measured in Joules (J)
Radiant Power - CORRECT ANSWER - -power that is emitted, transferred, or received in
the form of radiation; measured in Watts (W)
Radiant Exposure (H) - CORRECT ANSWER - -also called energy density
-radiant energy striking a surface divided by the area of that surface over which the striking
energy is distributed; measured in J/cm2
Irradiance (E) - CORRECT ANSWER - -also called power density
-radiant power striking a surface divided by the area of that surface over which the striking
energy is distributed; measured in W/cm2