Classification of Lasers
Manufacturers of lasers and laser products in the U.S. are regulated by
the Food and Drug Administration’s Center for Devices and
Radiological Health (FDA/ CDRH) under 21 CFR 1040. These
regulations require manufacturers to certify each laser or laser product
as belonging to one of four major Classes I, II, IIa, IIIa, IIIb, or IV.
The International Electro-technical Commission (IEC) is an
international standards body that writes laser safety standards.
Classification schemes are similar with Classes divided into Classes 1,
2, 3A, 3B, and 4. Lasers are classified according to the accessible
emission limits and their potential for causing injury. Lightwave
systems are generally classified as Class I/1, because, under normal
operating conditions, all energized laser transmitting circuit packs are
terminated on optical fibers which enclose the laser energy with the
fiber sheath forming a protective housing. Also, covers are typically in
place over the circuit pack shelves. The circuit packs themselves,
however, may be FDA/CDRH Class I or IIIb or IEC Class 1 or 3B.
Lightwave Safety Precautions
In its normal operating mode, a lightwave system is totally enclosed
and presents no risk of eye injury. It is a Class I/1 system under the
FDA and IEC classifications.
The lightguide cables that interconnect various components of a
lightwave system can disconnect or break, and may expose people to
lightwave emission. Also, certain measures and maintenance
procedures may expose the technician to emission from the
semiconductor laser during installation and servicing. Unlike more
familiar laser devices, such as solid-state and gas lasers, the emission
pattern of a semiconductor laser results in a highly divergent beam. In
a divergent beam, the irradiance (power density) decreases rapidly
with distance. The greater the distance, the less energy will enter the
eye, and the less potential risk for eye injury. Inadvertently viewing an
unterminated fiber or damaged fiber with the unaided eye at distances
greater than 5 to 6 inches normally will not cause eye injury provided
the power in the fiber is less than a few milliwatts at the shorter
wavelengths and a few tens of milliwatts at the longer wavelengths.
However, damage may occur if an optical instrument such as a
microscope, magnifying glass or eye loupe is used to stare at the
energized fiber end.
Laser Safety Information
General information
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365-312-761
Issue 1, May 2004
Lucent Technologies - Proprietary
See notice on first page
1 - 5
