ACTUAL Exam Questions and CORRECT
Answers
Diffuse Reflection - CORRECT ANSWER - Takes place when different parts of a beam
incident on a surface are reflected over a wide range of angles in accordance with Lambert's
Law. The intensity will fall off as the inverse of the square of the distance away from the surface
and also obey a Cosine Law of reflection.
pumping system - CORRECT ANSWER - uses photons from another source as a xenon
gas flash tube (optical pumping) to transfer energy to the media, electrical discharge within the
pure gas or gas mixture media (collision pumping)
laser medium - CORRECT ANSWER - can be a solid (state), gas, dye (in liquid), or
semiconductor. Lasers are commonly designated by the type of lasing material employed.
Solid state - CORRECT ANSWER - lasers have lasing material distributed in a solid
matrix, e.g., the ruby or neodymium-YAG (yttrium aluminum garnet) lasers. The neodymium-
YAG laser emits infrared light at 1.064 micrometers.
Gas - CORRECT ANSWER - lasers (helium and helium-neon, HeNe, are the most
common gas lasers) have a primary output of a visible red light. CO2 lasers emit energy in the
far-infrared, 10.6 micrometers, and are used for cutting hard materials.
Excimer - CORRECT ANSWER - 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 - CORRECT ANSWER - 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 - CORRECT ANSWER - 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.
Absorb - CORRECT ANSWER - To transform radiant energy into a different form, with a
resultant rise in temperature.
Absorption - CORRECT ANSWER - Transformation of radiant energy to a different form
of energy by the interaction of matter, depending on temperature and wavelength.
Accessible Emission Level - CORRECT ANSWER - The magnitude of accessible laser (or
collateral) radiation of a specific wavelength or emission duration at a particular point as
measured by appropriate methods and devices. Also means radiation to which human access is
possible in accordance with the definitions of the laser's hazard classification.
Accessible Emission Limit (AEL) - CORRECT ANSWER - The maximum accessible
emission level permitted within a particular class. In ANSI Z 136.1, AEL is determined as the
product of accessible emission Maximum Permissible Exposure limit (MPE) and the area of the
limiting aperture (7 mm for visible and near-infrared lasers).
Aperture - CORRECT ANSWER - An opening through which radiation can pass.
Argon - CORRECT ANSWER - A gas used as a laser medium. It emits blue-green light
primarily at 448 and 515 nm.
Attenuation - CORRECT ANSWER - The decrease in energy (or power) as a beam passes
through an absorbing or scattering medium.
Aversion Response - CORRECT ANSWER - Movement of the eyelid or the head to avoid
an exposure to a noxious stimulant, bright light. It can occur within 0.25 seconds, and it includes
the blink reflex time.