Fiber Optic :: Glossary :: T - W

Tap loss - In a fiber optic cable coupler is the ratio of power at the tap port to the power at the input port.

Tap port - In a fiber optic cable coupler in which the splitting ratio between output ports is not equal it is the output port containing the lesser power.

TDM - Time Division Multiplexing.

Tee coupler - A 3 port optical coupler.

10Base-F - A fiber optic cable based version of an IEEE 802.3 network.

10Base-FB - That portion of a 10Base-F network that defines the requirements for the fiber optic cable backbone network.

10Base-FL - That portion of a 10Base-F network that defines the fiber optic cable link between a concentrator and a station.

10Base-FP - That portion of a 10Base-F network that defines a passive star coupler.

10Base-T - A twisted pair cable version of an IEEE 802.3 network.

10Base-2 - A thin coaxial cable version of an IEEE 802.3 network.

10Base-5 - A thick coaxial cable version of an IEEE 802.3 network; very similar to the original Ethernet specification.

Ternary - Made from 3 different elements.

Thermal noise - Noise resulting from thermally induced random fluctuation in current in the receiver's load resistance.

Thermal stability - A measure of the insertion loss variation as the device undergoes various environmental changes.

Throughput loss - In a fiber optic cable coupler it is the ratio of power at the throughput port to power at the input port.

Tight buffer - Type of cable construction whereby each glass fiber optic cable is tightly buffered by a protective thermoplastic coating to a diameter of 900 microns. High tensile strength rating achieved, providing durability, ease of handling and ease of connectorization.

Time Division Multiplexing - TDM. A transmission technique whereby several low speed channels share a given transmission medium, for example a fiber optic cable. With this technique they share it on a time basis. Each channel is given specific time slots to transmit during and can only transmit during these time slots.

Token ring - A ring based networking scheme. A token is used to control access to the network. Used by IEEE 802.5 and FDDI.

Total bandwidth - The combined modal and chromatic bandwidth.

Total internal reflection - Total reflection of light back into a material when it strikes the interface of a material having a lower index at an angle below the critical angle.

Transduce - A device for converting energy from one form to another, such as optical energy to electrical energy.

Transceiver - A combination of transmitter and receiver providing both output and input interfaces with a device.

Transmission loss - Total loss encountered in transmission through a system.

Transmitter - In the context of a fiber optic cable based communication link an electrical package, which converts an electrical signal to an optical signal.

Tree coupler - A passive fiber optical component in which power from 1-input is distributed to more than 2-output fiber optic cables.

TX - Transmitter.

UL - Underwriters Laboratories, Inc.

Ultraviolet - Optical radiation for which the wavelengths are shorter than those for visible radiation, that is approximately between 1 nm and 400 nm.

Uniformity - The maximum insertion loss difference between ports of a coupler.

UV - Ultraviolet.

VCSL - Vertical cavity semiconductor laser.

Velocity of light - The velocity of light is 300,000 km/sec in a vacuum. In a medium it depends in the refractive index and the wavelength.

WAN - Wide Area Network. A network of connected computers that cover a great geographical area.

Waveguide - A 2 dimensional substrate which carries light in channels inscribed in the material.

Wavelength - Distance an electromagnetic wave travels in the time it takes to oscillate through a complete cycle. Wavelengths of light are measured in nanometers (10^-9 m) or micrometers (10^-6 m).

Wavelength dependence - The variation in an optical parameter caused by a change in the operating wavelength.

Wavelength Division Multiplexer - A passive fiber optical device used to separate optical signals of different wavelengths carried on 1 fiber optic cable.

Wavelength Division Multiplexing - WDM. Simultaneous transmission of several optical signals of different wavelengths on the same fiber optic cable. It is a technique used so that several different communications channels can share the same fiber optic cable.

WDM - Wavelength Division Multiplexing.

WIC - Wavelength Independent Coupler.

mW - MicroWatt.