Alcatel-Lucent 1643 AMS Installation Manual page 37

Safety
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, 1M, 2, 2M, 3B, 3R 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 circuit packs 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 circuit pack shelves. The circuit packs themselves,
however, may be FDA/CDRH Class I or IIIb or IEC Class 1, 1M, 3B, 3R or 4. State
of the art Raman and EDFA optical amplifiers have now extended into the Class IV/4
designations.
Lightwave safety precautions for optical fiber telecommununication systems
In its normal operating mode, an optical fiber telecommunication 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
telecommunication system 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 inches normally will not cause eye injury provided 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. 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.
Important! Use of controls, adjustments and procedures other than those specified
herein may result in hazardous laser radiation exposure.
Laser safety precautions for enclosed systems
Under normal operating conditions, optical fiber telecommunication systems are
completely enclosed; nonetheless, the following precautions shall be observed:
1. Because of the potential for eye damage, technicians should not stare into optical
connectors or broken fibers.
2. Under no circumstance shall laser/fiber optic operations be performed by a
technician before satisfactorily completing training in laser safety.
3. Since viewing laser emissions directly in excess of Class I/1 limits with an optical
instrument such as an eye loupe greatly increases the risk of eye damage.
....................................................................................................................................................................................................................................
365-312-802R7.2
Issue 4, June 2007
Alcatel-Lucent - Proprietary
See notice on first page
Laser safety
1-11