Page 50 - Market Analysis Report of Optical Communications Field in China & Global market 2020

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zone (35 °C ~ 50 °C), sensitization zone (60 °C ~ 85 °C Fig. 3-1 Additional attenuation of -70 oC~85 oC temperature
and -40 °C ~ -10 °C and -70 °C ~ -40 °C). A programmable cycle test
environmental thermostat is used to simulate the extreme
cold environment in laboratory. According to the above
divided areas as the assessment interval, the additional
attenuation characteristics of different types and
specifications of optical fibers are tested, and the test data
is used for summary analysis to obtain the optical fiber
using in the extremely cold environment. The attenuation
characteristic curve provides data support for engineering
construction operation and maintenance and product the ability of the fiber to resistant a temperature limit of -70
development. °C. The experimental fiber (the length of the fiber is not
less than 2.0 km) is placed in the environmental thermostat.
3.1 Temperature cycling experiment The temperature in the environmental thermostat is
In the process of the optical fiber cabling needs access to reduced from 23 °C to -70 °C, the cooling rate is 1 °C/
the short-term after high temperature, however, the cable min, and the temperature is reduced to -70 °C. During
used in extremely low temperature environment. In order the process of dropping 10 °C and dropping to -70 °C,
to ensure that the fiber changes dramatically in the external the additional attenuation of the 1310 nm and 1550 nm
environment temperature, the transmission properties of wavelengths was tested at regular intervals. At the same
optical fiber is still stable. time, the polarization mode dispersion coefficient (PMD)
of the experimental film was tested after the end of the
In order to evaluate the fiber whether maintain a good experiment.
performance at the extreme temperature of -70 °C ~ 85 °C,
the temperature cycle additional attenuation experiment is Figure 3-2 shows the average additional attenuation curves
carried out to study the newly exploited ultra-cold-resistant for the 1310nm and 1550nm wavelengths of the fiber at
& ultra-large capacity G.654.E fiber at -70 °C ~ 85 °C. extreme low temperatures. The experimental results show
The variation law of the additional attenuation of the fiber that the newly developed new ultra-high-capacity G.654.
after two cycles in the temperature range was studied. E fiber additional attenuation at 1310nm and 1550nm
The specific test method is: Placed the fiber (the length of wavelength is less than 0.01 dB/km; the additional
the fiber is not less than 2.0 km) into the environmental attenuation fluctuations have a tendency to decrease when
thermostat and the temperature in the thermostat is set to the fiber is kept at -70°C for 48h. The PMD of 1550 nm
-70 °C and 85 °C respectively, the cooling/heating rate wavelength is no more than 0.04 ps/km1/2.
is 1 °C/min. Kept for 2 hours when temperature achieves
the set value, and cycle number no less than twice. The Fig. 3-2 Low temperature resistant experiment
additional attenuation of the fiber is monitored in real time
during the test. At the same time, the polarization mode
dispersion coefficient (PMD) of the experimental film was
tested after the end of the experiment.

Figure 3-1 shows the temperature characteristic curve of
the new type of ultra-cold-resistant & ultra-large capacity
G.654.E fiber. The fiber is cycled for two cycles in a
temperature range of -70 °C to 85 °C. Four groups of
optical fibers were randomly selected for the corresponding Combined with the above experimental data, the current
test of a total of 10 h of two cycles. The results show that fiber has undergone a temperature cycle test of -70 ° C to
the additional attenuation at a wavelength of 1310 nm of 85 ° C and low temperature resistance test, the additional
the fiber is less than 0.01 dB/km. Moreover, the additional attenuation of the fiber does not change much. The fiber
attenuation in the second temperature cycle tends to after aging stress corrosion sensitivity parameter (Nd) is 23,
decrease compared with the first temperature cycle. The and the outer surface of the fiber has no obvious change,
PMD of 1550 nm wavelength is no more than 0.05 ps/ and the coating layer does not fall off.
km1/2.The new type of ultra-cold-resistant & ultra-large
capacity G.654.E fiber has the excellent properties of low 4.Conclusions
temperature resistance. This paper combines theoretical analysis with specific
experiments to explore the decay law of the new type
3.2 Low temperature resistant experiment of ultra-cold-resistant & ultra-large capacity G.654.
In practical applications, the fiber needs to maintain long- E fiber manufactured by the company under extreme
term stable performance to ensure stable and reliable environment. The results show that the new G.654.E fiber
performance of the cable. This requires the fiber to has an additional attenuation value of less than 0.01dB/km
maintain stable transmission characteristics even under at 1310nm and 1550nm in the -70°C~85°C temperature
extremely low temperature conditions. In order to verify continuing to page 43
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