Which two statements are true?

Which two statements are true?

• A. ITU-T G.652D is classified as low water peak or zero water peak single-mode fiber; ITU-T G.55 is single-mode fiber optimized for 1550-nm transmissions.
• B. ITU-T G.652D is not classified as low water peak fiber; ITU-T G.55 is not optimized for 1550-nm transmissions.
• C. ITU-T G.652D is classified as high water peak fiber; ITU-T G.55 is optimized for 1310-nm transmissions.
• D. Neither statement is true.

Answer: (A)

In optical fiber design, the water peak refers to absorption caused by OH- in the silica that historically limits performance around the 1380 nm region. A low water peak fiber minimizes this absorption, which makes the 1310 nm and especially the 1550 nm transmission windows practical for long-haul links. ITU-T G.652D is this kind of fiber: it’s classified as low water peak (often called zero water peak) single-mode fiber, optimized to support efficient operation at 1550 nm. The statement about G.55 aligns with this: it describes a single-mode fiber optimized for 1550-nm transmissions, which is exactly what many modern fibers are designed for to take advantage of the low-loss, dispersion characteristics of that window. So both parts line up with established fiber properties, making the first option true. The other options conflict with those facts—claiming G.652D isn’t low water peak, or that G.55 isn’t optimized for 1550 nm, would go against how these fibers are defined.

In optical fiber design, the water peak refers to absorption caused by OH- in the silica that historically limits performance around the 1380 nm region. A low water peak fiber minimizes this absorption, which makes the 1310 nm and especially the 1550 nm transmission windows practical for long-haul links. ITU-T G.652D is this kind of fiber: it’s classified as low water peak (often called zero water peak) single-mode fiber, optimized to support efficient operation at 1550 nm.

The statement about G.55 aligns with this: it describes a single-mode fiber optimized for 1550-nm transmissions, which is exactly what many modern fibers are designed for to take advantage of the low-loss, dispersion characteristics of that window.

So both parts line up with established fiber properties, making the first option true. The other options conflict with those facts—claiming G.652D isn’t low water peak, or that G.55 isn’t optimized for 1550 nm, would go against how these fibers are defined.