H3C S7500 Series Ethernet Switches Compliance and Safety Manual

Compliance and Safety Manual
H3C S7500 Series Ethernet Switches Chapter 3 Safety Information
3-7
3.4 Laser
The laser hazard level of this equipment is Class 1.
Warning:
When performing installation and maintenance operations of optical fibers, you should
not stand close to, or look into the optical fiber outlet directly with unaided eyes.
3.4.1 General Laser Information
Laser transceiver/ transmitter are used in optical transmission system and associated
test instruments. The wavelength of the laser is above 780nm, and lower than 1600nm.
Because the laser being transmitted through the optical fiber, produces a small beam of
light,it has very high power density and is invisible to human eyes. When a beam of light
enters the eyes, retinal may be burned.
The damage mechanism at the wavelengths used in telecommunications is thermal in
origin i.e., damage caused by heating. Therefore, a specific amount of energy is
required for a definite time to heat an area of retinal tissue.
Lasers used in lightwave systems have a larger beam divergence, typically 10 to 20
degrees. Inadvertently 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 instrument 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 the implementation of 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, so the ALS will shutdown
the laser emission in less than 100ms.
3.4.2 Laser Safety Guidelines
Read the following guidelines to avoid laser radiation:
z Read the relevant instructions before installation, operation and maintenance the
equipment. Ignoring the instructions can cause in exposure to dangerous laser
radiation.
z An eye-protective glasses are recommended when you are handling lasers or
fibers.