ACTUAL Exam Questions and CORRECT
Answers
Radiant Energy (Q) - CORRECT ANSWER - Energy that is emitted, transferred or
received. Measured in Joules (J)
Radiant Power - CORRECT ANSWER - Power emitted, transferred, or received in the
form of radiation. Measured in Watts (W)
Irradiance (E) - CORRECT ANSWER - (Power Density) Radiant power striking a surface
divided by the surface area W/cm2
Radiant Exposure (H) - CORRECT ANSWER - (Energy Density) Energy striking a
surface divided by the surface area exposed J/cm2
What does Laser stand for? - CORRECT ANSWER - Light Amplification by Stimulated
Emission of Radiation
What does a laser consist of? - CORRECT ANSWER - A Pumping System - Source of the
power that imparts energy to the atoms of the lasing medium to create photons
An Optical Cavity - Contains the medium, has mirrors and provides amplification/selection of
photons
Laser medium - Can be solid state matrix(ND:YAG), gaseous (HeNe 632.8nm red, CO2, Ar,Kr),
dye lasers (Rhodamine 6G), and semiconductor (Gallium Arsenide diode )
What are the two modes of laser operation? - CORRECT ANSWER - Continuous Wave -
Stable beam power over 0.25s
Pulsed -
Single Pulsed/Repetitively pulsed - Pulsed repetitively per second (Hz)
, Q-switched - stored PE to increase power before release
Mode Lock - Modulating standing waves of slightly different wavelengths combine to produce
short pulses
What are three characteristics of a laser beam - CORRECT ANSWER - Monochromatic -
Single wavelength
Coherent - Waves of laser light tightly in phase with each other
Collimated - Highly focused
What are the three main US Government agencies involved in laser regulation? - CORRECT
ANSWER - OSHA, Federal Aviation Administration (FAA) and FDA
What AFI covers the Laser Radiation protection program - CORRECT ANSWER - AFI
48-139 (minimum requirement for RPP) and DoD Instruction 6055.15, we also use ANSI
136.1(commercial)
What constitutes a class 1 laser? - CORRECT 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? - CORRECT 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? - CORRECT ANSWER - 3R - Marginally unsafe for
direct and specular viewing.
CW max 5mW