DA-6804+D Series
Installation and Operation Manual
55
Copyright © 2010, Harris Corporation
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 is an international standards body
that writes laser safety standards under IEC-60825. 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. Optical fiber telecommunication systems are generally classified
as Class I/1 because, under normal operating conditions, all energized laser
transmitting modules are terminated on optical fibers which enclose the laser
energy with the fiber sheath forming a protective housing.
Also, a protective housing/access panel is typically installed in front of the laser
modules frames. The modules themselves, however, may be FDA/CDRH Class I or
IIIb; or IEC Class 1, 3A, or 3B.
Laser Safety
Precautions
for Optical
Fiber Com-
munication
Systems
In its normal operating mode, an optical fiber communication 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 fiber optic cables that interconnect various components
of an optical fiber can disconnect or break, and may expose people to laser
emissions. 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 in. (127 to 152 mm) normally will not cause
eye injury, provided that the power in the fiber is less than a few milliwatts at the
near IR wavelengths and a few tens of milliwatts at the far IR wavelengths.
Laser Safety
WARNING: Use of controls, adjustments, and procedures other than
those specified in this document may result in hazardous laser
radiation exposure.
Optical fiber telecommunication systems use semiconductor laser transmitters that
emit infrared light that is normally not visible to the human eye. Although a
conventional laser produces a small beam of light, the power density is very high,
and it can damage your eyes.
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