NANOMETER (nm) A unit of length in the International System of Units (SI) equal
to one-billionth of a meter. Abbreviated nm - a measure of length. One nm equals
10(-9) meter, and is the usual measure of light wavelengths. Visible light ranges
from about 400 nm in the purple to about 760 nm in the deep red.
NANOSECOND One billionth (10(-9)) of a second. Longer than a picosecond or
femto-second, but shorter than a micro-second. Associated with Q-switched lasers.
Nd:GLASS LASER A solid-state laser of neodymium: glass offering high power
in short pulses. A Nd doped glass rod used as a laser medium to produce 1064 nm
Nd:YAG LASER Neodymium:Yttrium Aluminum Garnet. A synthetic crystal used as
a laser medium to produce 1064 nm light.
NEAR FIELD IMAGING A solid-state laser imaging technique offering control of
spot size and hole geometry, adjustable working distance, uniform energy distribution,
and a wide range of spot sizes.
NEMA Abbreviation for National Electrical Manufactures' Association, a group
which defines and recommends safety standards for electrical equipment.
NEODYMIUM (Nd) The rare earth element that is the active element in Nd:YAG
laser and Nd:Glass lasers.
NOISE Unwanted minor currents or voltages in an electrical system.
NOMINAL HAZARD ZONE (NHZ) The nominal hazard zone describes the space within
which the level of the direct, reflected or scattered radiation during normal
operation exceeds the applicable MPE. Exposure levels beyond the boundary of the
NHZ are below the appropriate MPE level.
NOMINAL OCULAR HAZARD DISTANCE (NOHD) The axial beam distance from the laser
where the exposure or irradiance falls below the applicable exposure limit.