1. In a medium of constant refractive index, n, the product of the geometric distance and the refractive index.
2. In a medium of varying refractive index, the integral of ns, where s is an element of length along the path, and n is the local refractive index.
Note: Optical path length is proportional to the phase shift that a… (Read More →)

The extra optical power required to account for degradations due to reflections, intersymbol interference, and mode partition noise. [T1.646-1995]

See radiant power.

In a fiber-optic communication link, the allocation of available optical power (launched into a given fiber by a given source) among various loss-producing mechanisms such as launch coupling loss, fiber attenuation, splice losses, and connector losses, in order to ensure that adequate signal strength (optical power) is available at the receiver.
Note 1: The optical power budget is usually specified… (Read More →)

In an optical communications link, the difference between (a) the optical power that is launched by a given transmitter into the fiber, less transmission losses from all causes, and (b) the minimum optical power that is required by the receiver for a specified level of performance.
Note 1: The optical power margin is usually expressed in dB. At least several… (Read More →)

A device that detects an optical signal, converts it to an electrical signal, and processes the electrical signal as required for further use.

See optical repeater.

In an optical communication system, an optoelectronic device or module that receives an optical signal, amplifies it (or, in the case of a digital signal, reshapes, retimes, or otherwise reconstructs it), and retransmits it as an optical signal.

The ratio (in dB) of optical power arriving at the interface (P1) to the optical power reflected back from the same interface (P2). [T1.106-1988]

The part of the physical plant consisting of the fiber-optic cabling and connectors interconnected to provide the transport function between two adjacent repeater locations, between a repeater location and an adjacent terminal location, or between two adjacent terminal locations. The optical section extends between the point on the optical fiber just after the transmitter optical connector and the point on… (Read More →)