H31-341_V2-5 practice question 6 of 15

Which of the following fiber types complies with the description that the dispersion at 1310 nm is 0 and the typical dispersion coefficient around 1550 nm is 17 ps/nm.km?

Full set: 60 questions
Answer options
A: G.654
B: G.652 Correct answer
C: G.655
D: G.653
Correct Answer:
B. G.652
Explanation

The ITU-T G.652 standard defines the characteristics of standard single-mode fiber (SSMF). A key attribute of G.652 fiber is its zero-dispersion wavelength (λ₀) located in the 1310 nm window (specifically, between 1300 nm and 1324 nm). Consequently, when operating in the 1550 nm window, where optical attenuation is lowest, this fiber exhibits a significant positive chromatic dispersion. The typical dispersion coefficient value for G.652 fiber at 1550 nm is approximately +17 ps/(nm·km). These two characteristics—zero dispersion at 1310 nm and ~17 ps/(nm·km) dispersion at 1550 nm—are the defining features of G.652 fiber.

Why Incorrect

A. G.654: This fiber is optimized for low attenuation and a large effective area, primarily for submarine systems. Its dispersion characteristics are similar to G.652 but are not its defining feature.
C. G.655: This is a Non-Zero Dispersion-Shifted Fiber (NZ-DSF) with a small but non-zero dispersion value (e.g., 1-6 ps/nm.km) at 1550 nm to mitigate nonlinear effects in DWDM systems.
D. G.653: This is a Dispersion-Shifted Fiber (DSF) where the zero-dispersion wavelength is intentionally shifted to the 1550 nm window to minimize dispersion and attenuation simultaneously.

References

1. Huawei Certified ICT Professional - Transmission V2.0 Training Material. (Document ID: H31-341). In the module "WDM System Components," the section on optical fibers specifies that G.652 fiber has a zero-dispersion wavelength at 1310 nm and a dispersion coefficient of about 17 ps/(nm·km) at 1550 nm.

2. ITU-T Recommendation G.652. "Characteristics of a single-mode optical fibre and cable" (April 2022). Section 6.3 and Table 1 for G.652.D specify the zero-dispersion wavelength (λ₀) to be in the range 1300-1324 nm. The typical dispersion slope at λ₀ allows for the calculation of the dispersion at 1550 nm, which is widely established as ~17 ps/(nm·km).

3. Agrawal, G. P. (2013). Fiber-Optic Communication Systems (4th ed.). Wiley. In Chapter 2, "Optical Fibers: Structures, Waveguiding, and Fabrication," Section 2.3.2 discusses the properties of G.652 fiber, stating its zero-dispersion wavelength is near 1.31 μm and its dispersion at 1.55 μm is approximately 17 ps/(km-nm).

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