
APPENDIX
B–70115EN/03
H. GLOSSARY
468
H
GLOSSARY
Name Meaning
Access panel That protective component of a housing or
enclosure which, when removed or shifted, can
cause exposure to laser radiation
AEL Accessible
emission level
Maximum accessible emission level set up for each
class of laser products
Alighment Optical axis adjustment
Aperture Iris, or stop
Beam Aggregate of unidirectional, diverging, or conversing
rays
Beam diameter Distance between two symmetrical points in a cross
section of a beam where the power per unit area is
86.5% of the maximum power per unit area
Beam divergence Angle through which a beam spreads
Burn pattern Laser beam mode pattern generated on a plate such
as an acrylic plate for confirmation purposes
Circular Polarization Polarization in which a plane of polarization rotates
about the axis along which the light progresses and
does not have directivity; an electric or magnetic
field based on circular polarization has a constant
intensity.
CO
2
laser Laser that uses a carbon dioxide gas as a laser
medium
CW Continuous wave Continuously radiated laser output
Diode Laser Laser that uses a semiconductor as an exciting me-
dium
Discharge excitation Realization of inverted population by means of dis-
charge
Enhanced pulse Pulse peak output, greatly amplified relative to CW
rated output
Excitation Transition of atoms or molecules to a higher energy
level by supplying them with external energy
Exposure time Duration through which laser radiation is emitted
Fast axial flow laser Laser in which gas flows rapidly in the same direc-
tion as the laser beam