We’re always talking about how fast fiber optic networks are, but “fast” has several meanings. How well do you understand fast in fiber optics?
Created by: Jim Hayes
1. When we talk about how fast fiber optics is, we really mean fiber optics _______.
A. Transmits signals from one point to another faster than other media
B. Transmits signals at higher bit rates than other media
C. Is quicker to install than other communications media
D. Dominated the communications market so quickly
2. The original fiber optic telecom networks operated at 145 Mbps, about _______ times faster than the typical digital copper or wireless networks of the era.
3. Multimode optical fiber was originally optimized for a bandwidth at _______ nm wavelength, where attenuation was lower to allow longer telecom links.
4. The first 100 Mbps fiber optic LAN FDDI (fiber distributed data interface), was designed around fiber optics.
5. Single-mode fiber was introduced in the mid-1980s and immediately dominated telecom because it offered _______ and _______. (Choose two)
A. Virtually infinite bandwidth
B. Much lower attenuation
C. Operation with cheaper laser sources
D. A much lower cost
6. The next big step up in single-mode fiber bandwidth came from the introduction of _______ division multiplexing in the late 1990s.
7. Long-distance single-mode networks above 100 Gbps are now moving to a new type of system called _______ that greatly increases transmission links’ capability.
A. Quantum entanglement
B. Holographic encapsulation
C. Coherent transmission
D. Frequency synthesis
8. Many LANs still use _______ fiber because it was adequate for the speed and distances in these networks.
A. Plastic optical
9. When LANs reached 1 Gbps, the LED sources could not provide adequate speed, so the _______, a new type of inexpensive laser, was needed.
A. He-Ne (helium-neon) laser
B. DFB (distributed feedback) laser
C. F-P (Fabry-Perot) laser
D. VCSEL (vertical-cavity surface-emitting laser)
10. The speed of a pulse transmitted down an optical fiber is actually only two-thirds the speed of light in a vacuum because light slows down in glass compared to its speed in air or the vacuum of space.