Question | Answer |
Absorption | Light interaction with the atomic structure of the fiber material; also involves the conversion of optical power to heat |
Backbone | The primary path for data traffic to and from destinations and sources in the campus network |
Chromatic Dispersion | The broadening of a pulse due to different propagation velocities of the spectral components of the light pulse |
Cladding | Material surrounding the core, which must have a lower index of refraction to keep the light in the core |
Dense Wavelength Division Multiplex (DWDM) | Incorporates the propagation of several wavelengths in the 1550-nm range for a single fiber |
Dispersion | Broadening of a light pulse as it propagates through a fiber strand |
Dispersion Compensating Fiber | Acts like an equalizer, canceling dispersion effects and yielding close to zero dispersion in the 1550-nm region |
Distributed Feedback (DFB) Laser | A more stable laser suitable for use in DWDM systems |
DL | Diode laser |
DS | Digital signal |
DSL | Digital subscriber line |
Event | A disturbance in the light propagating down a fiber span that results in a disturbance on the OTDR trace |
Fiber Bragg Grating | A short strand of modified fiber that changes the index of refraction and minimizes intersymbol interference |
Fiber Cross-connect | Optical patch panel used to interconnect fiber cables |
Fiber, Light Pipe, Glass | Terms used to describe a fiber-optic strand |
FTTB | Fiber to the business |
FTTC | Fiber to the curb |
FTTD | Fiber to the desktop |
FTTH | Fiber to the home |
Fusion Splicing | A long-term method where two fibers are fused or welded together |
GBIC | Gigabit interface converter |
Graded-index Fiber | The index of refraction is gradually varied with a parabolic profile |
IC | Interconnect fibers branch exchange-item D shows the jumpers connecting the main fiber cross-connect (item B) to the active equipment (item C) |
IDC | Intermediate distribution closet |
Index-matching Gel | A jellylike substance that has an index of refraction much closer to glass than to air |
Infrared Light | Light extending from 680 nm up to the wavelengths of the microwaves |
Isolator | An inline passive device that allows optical power to flow only in one direction |
LED | Light-emitting diode |
Logical Fiber Map | Shows how the fiber is interconnected and data is distributed throughout a campus |
Long Haul | The transmission of data over hundreds or thousands of miles |
Macrobending | Loss due to light breaking up and escaping into the cladding |
Mechanical Splices | Two fibers joined together with an air gap, thereby requiring an index-matching gel to provide a good splice |
Microbending | Loss caused by very small mechanical deflections and stress on the fiber |
mm | Multimode |
Modal Dispersion | The broadening of a pulse due to different path lengths taken through the fiber by different modes |
Mode Field Diameter | The actual guided optical power distribution, which is typically a micron or so larger than the core diameter; single-mode fiber specifications typically list the mode field diameter. |
Multimode Fiber | A fiber that supports many optical waveguide modes |
Numerical Aperture | A measure of a fiber's ability to accept light |
Optical Ethernet | Ethernet data running over a fiber link |
Optical Spectrum | Light frequencies from the infrared on up |
Physical Fiber Map | Shows the routing of the fiber but also shows detail about the terrain, underground conduit, and entries into buildings |
Polarization Mode Dispersion | The broadening of a pulse due to the different propagation velocities of the X and Y polarization components of the light pulse |
Pulse Dispersion | Stretching of received pulse width because of multiple paths taken by the light |
Received Signal Level (RSL) | The input signal level to an optical receiver |
Refractive Index | Ratio of the speed of light in free space to its speed in a given material |
SC, ST, FC, LC, MT-RJ | Typical fiber connectors on the market |
Scattering | Caused by refractive index fluctuations; accounts for 96 percent of attenuation loss |
Single-mode Fiber | Fiber cables with core diameters of about 7-10 μm; light follows a single path |
sm | Single mode |
SONET/SDH | Synchronous optical network; protocol standard for optical transmission in long-haul communication/synchronous digital hierarchy |
STS | Synchronous transport signals |
Tunable Laser | Laser in which the fundamental wavelength can be shifted a few nanometers, ideal for traffic routing in DWDM systems |
Vertical Cavity Surface Emitting Lasers (VCSELs) | Lasers with the simplicity of LEDs and the performance of lasers |
XENPAK, XPAK, X2, XFP, SFP+ | The ten gigabit interface adapter |
Zero-dispersion Wavelength | Point where the dispersion is actually zero |
| memorize |