FON quiz 15 (module 1 part 2)

The fibers mostly not used nowadays for optical fiber communication system are

• a) Single mode fibers

• b) Multimode step fibers

• c) Coaxial cables

• d) Multimode graded index fibers

Single mode fibers allow single mode propagation; the cladding diameter must be at least

• a) Twice the core diameter

• b) Thrice the core diameter

• c) Five times the core diameter

• d) Ten times the core diameter

What is needed to predict the performance characteristicsics of single mode fibers?

• a) The intermodal delay effect

• b) Geometric distribution of light in a propagating mode

• c) Fractional power flow in the cladding of fiber

• d) Normalized frequency

A single mode fiber has mode field diameter 10.2μmand V=2.20. What is the core diameter of this fiber?

• a) 11.1μm

• b) 13.2μm

• c) 7.6μm

• d) 10.1μm

How many propagation modes are present in single mode fibers?

• a) One

• b) Two

• c) Three

• d) Five

Numerical aperture is constant in case of step index fiber. State whether the statement is true or false.

• a) True

• b) False

Plastic fibers are less widely used than glass fibers. State whether the statement is true or false.

• a) True

• b) False

Photonic crystal fibers also called as

• a) Conventional fibers

• b) Dotted fibers

• c) Stripped fibers

• d) Holey fibers

Losses in photonic crystal fibers are reduced to a level of

• a) 0.1dB/km

• b) 0.2dB/km

• c) 0.3dB/km

• d) 0.4dB/km

In index-guided photonic crystal fiber structure, the dark areas are air holes. What does white areas suggests?

• a) Air

• b) Silica

• c) Water

• d) Plasma