IT2 Test Final draft (Computers / networking) PT2
person that collected 4 fundamental equations that completely describe behavior of em fields
James Clerk Maxwell
layer of material that surrounds core in optical fiber
cladding
spreading of light as light propagates along a fiber
dispersion
optical fiber made out of plastic
plastic optical fiber
# of diff types of fiber optic optical transmitters
3
fiber optic installation standard for ships
MIL-STD 2042B
spectral width of a laser diode
.1nm-3nm
index of refraction for air
1.00
index of refraction for glass
1.50
about how many times more sensitive is the APD compared to the PIN photodiode which allows it to respond better to faster incoming sig
10
average lifespan of LEDs
10 years
# of modes propagated by multimode fibers
100
data rates can be reached w VCSELs over a distance of a few hundred meters
10Gbps
in silica glass, the wavelengths of op range from 700nm to how many nm
1600
year John Tyndall demonstrated light used internal reflection to follow a specific path
1854
approx speed of light
186,000 miles per second
year that Dr. Robert Maurer, Donald Keck, and Peter Schultz succeded in dev glass fiber that exhibited attenuation at less than 20dB/km, making fiber optics viable
1970
year there was a fiber optic telephone link installed on USS Little Rock
1973
year the ALOFT program dev by Air Force
1976
year fiber optic hone sys installed in Chicago and Boston by AT&T and GTE
1977
# of basic types of optical fibers
2
# of diff methods used to describe how light is xmitted along optical fiber
2
# of diff types of rays can propagate along an optical fiber
2
# of parts the basic structure of an optical fiber consist of
3
# of primary wavelength windows used w fiber optics
3
OM3 fibers provide suff bandwidth to support 10Gb Ethernet up to how many meters
300
part a fiber optic data link consists of
4
# of diff types of dispersion there are
5
# of volts of biasing are req by PIN photodiodes
5
size of multimode laser optimized fiber must be used as the transmission medium for VCSEL
50 micron
OM4 fibers provide suff bandwidth to support 10Gb Ethernet up to how many meters
550
max modulation rate of LEDs since they cannot be turned off/on fast enough to support higher bandwidth
622 Mbit/s
LEDs utilized in LANs where transmissions of less than 2km are required usually don't exceed what speed
680Mbps/km
# of micrometers the typical core size of single mode fiber is
8-10
wavelengths LEDs operate on
850nm and 1300nm
fiber optics design standard for ships
MIL-STD 2052
type of cable supports 125m links at 40 and 100Gbit/s
OM4
type of photodiode has a lightly doped intrinsic layer which separates the more heavily doped p material w free electrons or p mat w holes
PIN
law used to describe relationship between incident and refracted rays at ray boundary
Snell's law of refraction
defined as portion of attenuation resulting from conversion of optical power to another form
absorption
angle between incident wave and normal
angle of incidence
angle between normal and path of light wave thru second medium
angle of refraction
jacket color that is recommended for 50/125 um laser optimized OM3 and OM4 fiber
aqua
difference or loss of power sent from transmitter to what arrives at the receiver defined as
attenuation
reduces amount of optical power xmitted by fiber
attenuation
calss of meridional rays remain in the core and propagate along the axis of the fiber
bound
who developed the optical telegraph?
claude chappe
layer of mat that surrounds cladding in optical fiber
coating/buffer
unit of measurement used in optics to describe loss or attenuation
decibel
spreading of a pulse of light as it travels down the length of an optical fiber that limits the bandwidth or info carrying capacity of a fiber
dispersion
spreads optical pulse as it travels along fiber
dispersion
spreading of a light beam called as it travels from its source
divergence
type of absorption is caused by impurities intro into the fiber mat
extrinsic
optical cavity in a LASER
fabry perot cavity
xmission medium that is immune to electrical noise
fiber
sends input data thru fiber optic components & provides this data as output info
fiber optic data link
used to convert optical energy to electrical energy
fiber optic detector
optical tech = radiant power thru fibers
fiber optics
fiber optics user what to transmit light?
glass fibers
wave that strikes a reflecting surface
incident
measures speed of light in optical medium
index of refraction
type of absorption that's caused by basic fiber mat properties
intrinsic
invention prompted researchers to study potential of fiber optics for data comms, sensing, and other apps
laser
law states that angle of incidence is equal to angle of reflection
law of reflection
type of dispersion that occurs bc diff wavelengths also travel at diff velocities thru a fiber, even in same mode
material
type of rays pass thru the axis of optical fiber
meridional
small microscopic bends of the fiber axis that occur mainly when a fiber is cabled
microbends
scattering- if the size of the defect is greated than one tenth of the wavelength of light
mie scattering
effect caused by diff speeds of individual modes in a ligtht pulse
modal dispersion
theory describes behavior of light within optical fiber
mode
exchange of power between 2 modes
mode coupling
set of guided em waves in relation to optical fiber
modes
modal dispersion only occurs in these types of fibers
multimode
optical fiber that operates below the cutoff wavelength
multimode fiber
imaginary line perpendicular to the point at which incident wave strikes the reflecting surface
normal
determines how many modes a fiber can support
normalized freq
msrmnt of the ability of an optical fiber to capture light
numerical aperture
type of substance reflects/absorbs all light rays that fall upon them
opaque
most common type of fiber optic detector
photodiode
Quanta know as when referring to light energy
photons
type of wave whose surfaces of constant phase are infinite parallel planes normal to the direction of propagation
plane
type of optical fiber has silica based core and plastic cladding w lower perf, high xmission loss, & lower bandwidth than glass fiber
plastic clad silica
theory used to approx the light acceptance and guiding properties of optical fibers
ray
main source of loss in commercial fibers op between 700nm and 1600nm wavelength
rayleigh scattering
type of losses caused by interaction of light w density fluctuations within a fiber
scattering
type of fibers that are predominately used in fiber optics bc of their low intrinsic mat absorption at the wavelengths of op
silica
optical fiber that operates above the cutoff wavelength
single mode fiber
type of fiber is waveguide dispersion the most significant
single-mode
type of rays travel thru optical fiber w/o passing thru its axis
skew
specifies range of wavelength that can propagate in the fiber
spectral width
substances thru which some light rays can pass, but thru which obj cannot be seen clearly because the rays are diffused`
translucent
type substance xmit almost all light waves falling upon them
transparent
type of wave motion is represented by motion of water
transverse-wave motion
short range high data rate transmitter for fiber optic data links
vertical cavity surface emitting laser (VCSEL)
recurring disturbance advancing thru space w or w/o use of physical medium
wave motion
type of dispersion occurs bc the mode propagation constant is a function of the size of the fibers core relative to the wavelength of operation
waveguide
distance measured in nanometers from crest of one wave to the crest of the next
wavelength
typical NA values for glass fibers
0.20-0.29
types of optical fibers classified into
2
max distance of hard clad silica fibers
2Km