OADM: See optical add/drop multiplexer. |
| OAM: Abbreviation for operation, administration, and maintenance.
Refers to telecommunications networks. |
OAN: Abbreviation for optical access network.
A network technology, based on passive optical networks (PONs),
that includes an optical switch at the central office,
an intelligent optical terminal at the customer’s
premises, and a passive optical network between
the two, allowing services providers to deliver fiber-to-the-home while eliminating the expensive electronics
located outside the central office. |
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| OCH: See optical channel. |
| OC-x: Abbreviation
for optical carrier. A carrier rate specified
in the SONET standard. |
| ODN: Abbreviation for optical distribution network. Term for
optical networks being developed for interactive
video, audio, and data distribution. |
| O/E: Abbreviation for optical-to-electrical converter.
A device used to convert optical signals to
electrical signals. Also known as OEC. |
|
| OEIC: Abbreviation
for opto-electronic integrated circuit. An integrated circuit that
includes both optical and electrical elements. |
| OEM: Abbreviation
for original equipment manufacturer. The manufacturer
of any device that is designed and built to
be distributed under the label of another company. |
| OLT: Abbreviation for optical line termination. Optical network
elements that terminate a line signal. |
| OLTS: Abbreviation
for optical loss test set. A source and optical power meter combined used to
measure optical loss. |
| OMS: Abbreviation
for optical multiplex section. A section of
a DWDM system that incorporates an optical add/drop multiplexer. |
|
| ONI: Abbreviation for optical network interface.
A device used in an optical distribution network
to connect two parts of that network. |
|
ONT:
Abbreviation for optical network termination.
Optical network element that terminates a
line signal in installations where the fiber
extends into the customer premises. |
| ONU: Abbreviation for optical network unit. A network element
that is part of a fiber-in-the-loop system. |
| OOI: Abbreviation for open optical interface. A point at which
an optical signal is passed from one equipment
medium to another without conversion to an electrical
signal. |
| Open Systems Interconnection (OSI): Pertaining
to the logical structure for communications
networks standardized by the International Organization
for Standardization (ISO). |
| Optical Add/Drop Multiplexer (OADM): A device
which adds or drops individual wavelengths from
a DWDM system. |
|
| Optical Amplifier: A device that amplifies an input optical signal
without converting it into electrical form.
The best developed are optical fibers doped
with the rare earth element, erbium. See also EDFA. |
|
| Optical Bandpass: The range of optical wavelengths which can be
transmitted through a component. |
| Optical Channel: An optical wavelength band for WDM optical communications. |
| Optical Channel Spacing: The wavelength separation between adjacent WDM channels. |
|
| Optical Channel Width: The optical
wavelength range of a channel. |
| Optical Continuous Wave Reflectometer (OCWR): An instrument used to characterize
a fiber optic link wherein an unmodulated signal is transmitted
through the link, and the resulting light scattered and reflected
back to the input is measured. Useful in estimating
component reflectance and link optical return
loss. |
| Optical
Directional Coupler (ODC): A component
used to combine and separate optical power. |
 |
| Optical Fall Time: The
time interval for the falling edge of an optical pulse to transition from
90% to 10% of the pulse amplitude. Alternatively,
values of 80% and 20% may be used. |
 |
| Optical Fiber: A glass
or plastic fiber that has the ability to guide
light along its axis. The three parts of
an optical fiber are the core, the cladding, and the coating or buffer. |
 |
| Optical Isolator: A
component used to block out reflected and unwanted
light. Also called an isolator. |
 |
| Optical Link Loss Budget: The range of optical loss over which
a fiber optic link will operate and meet all specifications. The
loss is relative to the transmitter output
power and affects the required receiver input power. |
Click image to enlarge. |
| Optical Path Power Penalty: The additional loss budget required
to account for degradations due to reflections,
and the combined effects of dispersion resulting
from intersymbol
interference, mode-partition noise, and
laser chirp. |
 |
| Optical Power Meter: An instrument that measures the amount of optical
power present at the end of a fiber or cable. |
 |
| Optical
Pump Laser: A shorter wavelength laser used to pump a length
of fiber with energy to provide amplification
at one or more longer wavelengths. See also EDFA. |
| Optical
Return Loss (ORL): The ratio (expressed
in dB) of optical power reflected
by a component or an assembly to the optical
power incident on a component port when that
component or assembly is introduced into a link
or system. |
| Optical Rise Time: The
time interval for the rising edge of an optical pulse to transition from
10% to 90% of the pulse amplitude. Alternatively,
values of 20% and 80% may be used. |
|
| Optical Signal-to-Noise-Ratio
(OSNR): The optical equivalent
of SNR. |
| Optical Spectrum Analyzer (OSA): A
device that allows the details of a region of
an optical spectrum to be resolved. Commonly
used to diagnose DWDM systems. |
 |
| OTDR (Optical Time Domain Reflectometer): An instrument that
locates faults in optical fibers or infers attenuation by backscattered light
measurements. |
 |
| Optical
Waveguide: Another name for optical fiber. |
| OSA: See optical spectrum analyzer. |
| OSNR: See optical signal-to-noise ratio. |
| Outside Plant (OSP): In telephony,
all cables, conduits, ducts, poles, towers,
repeaters, repeater huts, and other equipment
located between a demarcation point in a switching
facility and a demarcation point in another
switching facility or customer premises. |
 |
| OXC: Abbreviation for optical cross-connect.
See cross-connect. |
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