Note: The data and dimensions contained in this catalog are intended for use as a guide and are subject to change and/or update by BEA Electro Sales, Inc. without
notice. Every care has been taken to ensure that the information contained within this catalog is accurate from the date of publication. BEA Electro Sales will not
accept responsibility for damage, loss, or expense resulting from any error or omission contained herein. Furthermore, all products are sold with the understanding
that users will perform all necessary tests to determine the suitability of these products for their intended use.
WHATISALASER?
LASER is an acronym which stands for Light Amplification by
Stimulated Emission of Radiation. The energy generated by the laser
is in or near the optical portion of the electromagnetic spectrum (see
Figure 1). Energy is amplified to extremely high intensity by an atom-
ic process called stimulated emission. The color of laser light is nor-
mally expressed in terms of the laser’s wavelength. Nanometer (nm)
is the most common unit used in expressing a laser’s wavelength.
LASER HAZARDS & BEAM HAZARDS
The laser produces an intense, highly directional beam of light.
If directed, reflected, or focused upon an object, laser light will be
partially absorbed, raising the temperature of the surface and/or the
interior of the object, potentially causing an alteration or deforma-
tion of the material. Lasers can also cause tissue damage. Today, most
high-power lasers are designed to minimize access to laser radiation
during normal operation. Lower-power lasers may emit levels of laser
light that are not a hazard.
LASER HAZARDS CLASSIFICATION
The Center for Devices and Radiological Health, a division of the
Food and Drug Administration regulates the manufacturing and
classification of laser products. The laser classes help group lasers
by their hazard potential, and identifies these classes based on their
optical emission (wavelength, exposure time, output power).
GENERAL GUIDELINES FOR
CW LASER CLASSIFICATION
Class I Lasers or laser systems that do not, under normal
operating conditions, pose a hazard.
Class IIa Low power visible lasers or laser systems that are not
intended for prolonged viewing, and under normal operating
conditions will not produce a hazard if the beam is viewed directly
for periods not exceeding 1000 seconds.
Class II Low power visible lasers or laser systems which, because
of the normal human aversion response, do not normally present a
hazard, but may present some potential for hazard if viewed directly
for extended periods of time (like many conventional light sources).
Class IIIa Lasers or laser systems having a CAUTION label that
normally would not injure the eye if viewed for only momentary
periods (within the aversion response period) with the unaided
eye, but may present a greater hazard if viewed using collecting
optics. Another group of Class 3a lasers have DANGER labels and
are capable of exceeding permissible exposure levels for the eye
in 0.25 seconds and still pose a low risk of injury.
Class IIIb Lasers or laser systems that can produce a hazard if viewed
directly. This includes intrabeam viewing of specular reflections. Class
3B lasers will not normally produce a hazardous diffuse reflection.
Class IV Lasers or laser systems that produce a hazard not only from
direct or specular reflections, but may also produce hazardous
diffuse reflections. Such lasers may produce significant skin hazards
as well as fire hazards.
The information mentioned here is intended to be an introduction
to lasers and laser safety, and should not be considered to be an
authoritarian guide. A better informed user has the knowledge to
make safer decisions: learn about safety procedures for your class
of laser, and the next class higher.
An excellent source for laser safety is the Laser Institute of America.
A very useful resource is their web-based Safety Bulletin and printed
Laser Safety Guide.
LASER DIODE MODULE GLOSSARY
Term Definition
Angstrom Metric unit equal to 10-10 meter.
Beam Diameter Calculated distance between two exactly
opposed points on a beam at a chosen
fraction of peak power.
Beam Divergence Increase in the diameter of an initially
collimated beam as measured in
milliradians (mrad) at specified points.
CDRH Center for Devices and Radiological Health.
CW Continuous Wave.
LASER Light Amplification by Stimulated Emission
of Radiation.
Laser Diode Module Small semiconductor laser packaged
in a durable housing.
Micron One-millionth of a meter (1µm = 10-6m).
Milli Prefix for one-thousandth (10-3).
Millimeter 0.001 meter.
MRad Milli-Radian; 1/1000 of a radian used to
specify laser beam divergence.
Nanometer One-billionth of a meter (1nm = 10-9m).
Watt Unit of power that produces energy
at the rate of 1 joule per second.
Wavelength Electromagnetic energy transmitted
in the form of a sinusoidal wave;
the physical distance covered by one
cycle of this wave. Wavelength is inversely
proportional to frequency.