User's Manual

Compliance and Safety Manual
3 Safety Information
Issue (2011-06-25)
Huawei Technologies Proprietary
3-11
WARNING
When handling optical fibers, do not stand close to, or look at the optical fiber outlet directly
with unaided eyes.
3.4.1 General Laser Information
Laser transceivers or transmitters are used in the optical transmission system and associated
test tools. The wavelength of the laser is between 780 nm and 1600 nm. Because the laser is
transmitted through the optical fiber, it has very high power density and is invisible to human
eyes. When a beam of light enters the eye, the retina may be damaged.
Laser of wavelengths used in telecommunications can cause thermal damage to the retina.
Lasers used in lightwave systems have a larger beam divergence, typically 10 to 20 degrees.
Viewing an un-terminated fiber or damaged fiber with the unaided eye at distances greater
than 150 mm (6 inches) will normally not cause eye injury. However, damage may occur if an
optical tool such as a microscope, magnifying glass or eye loupe is used to view the energized
fiber end.
In its normal operating mode, a lightwave system is totally enclosed and presents no risk of
eye injury. Additional safety is achieved by an automatic laser shut-down (ALS) of the system.
The ALS, however, can be applied for bi-directional transmission only. If the receiver side
does not detect the laser from the transmission side, it will give the transmission side a signal.
Upon receiving the signal, the ALS will shut down the laser emission within 100 ms.
3.4.2 Laser Safety Guidelines
Read the following guidelines to avoid laser radiation:

Read the instructions before installing, operating and maintaining the device. Ignoring
the instructions can cause exposure to dangerous laser radiation.

Wear a pair of eye-protective glasses when you are handling lasers or fibers.

All the operation shall be performed by personnel who have completed the approved
training courses.

Make sure that the optical source is switched off before disconnecting optical fiber
connectors.

Before opening the front door of an optical transmission system, make sure that you are
not exposed to laser radiation.

Do not look at the end of an exposed fiber or an open connector when you are not sure
whether the optical source is switched off or not.

Use an optical power meter to check and ensure that the optical source is switched off by
measuring the optical power.

Do not use an optical tool such as a microscope, a magnifying glass or an eye loupe to
view the optical connector or fiber.
3.4.3 Handling Fibers
Read the instructions before handling fibers.