This results in simpler photonic lines, less equipment, and lower costs-while, of course, increasing bandwidth significantly. It provides more margin, allowing higher bit-rate signals to traverse farther distances. High-gain soft-decision Forward Error Correction (FEC), which enables signals to traverse longer distances while requiring fewer regenerator points.This results in greater flexibility in line rates, with scalability from 100G to 400G and beyond per single signal carrier, delivering increased data throughput at a lower cost per bit.Īdvanced coherent optical technology has a number of key attributes, including: Coherent optics enables greater network flexibility and programmability by supporting different baud rates and modulation formats. Digital signal processors electronically compensate for Chromatic and Polarization Mode Dispersion (CD and PMD) to enable robust performance over old and new fibers alike, and eliminate the need for dispersion-sloped compensating modules from the photonic line. This, in turn, imparts considerably more information onto the light speeding through a fiber optic cable.Ĭoherent optics provides the performance and flexibility to transport significantly more information on the same fiber.Ĭoherent optical technology forms the foundation of the industry’s drive to achieve transport speeds of 100G and beyond, delivering Terabits of information across a single fiber pair. It takes the typical ones and zeroes in a digital signal-the blinking on and off of the light in the fiber-and uses sophisticated technology to modulate the amplitude and phase of that light and send the signal across each of two polarizations. Network capacities are increasing by 25 to 50 percent every year, and systems running at 10 Gb/s just cannot keep up with this kind of rapid scalability.Ĭoherent optics solves the capacity problems network providers are facing. On-demand content, bandwidth-hungry mobile apps, high-definition video streaming, and new cloud-based IT applications are driving massive scale and unpredictable traffic patterns. The degree of coherence is measured by the interference visibility, a measure of how perfectly the waves can cancel due to destructive interference.It’s a web-scale world. Two waves are said to be coherent if they have a constant relative phase. When interfering, two waves can add together to create a wave of greater amplitude than either one or subtract from each other to create a wave of lesser amplitude than either one, depending on their relative phase. This implies that constructive or destructive interferences are limit cases, and that waves can always interfere, even if the result of the addition is complicated or not remarkable. In quantum mechanics, a single wave can interfere with itself, but this is due to its quantum behavior and is still an addition of two waves. Interference is nothing more than the addition, in the mathematical sense, of wave functions. More generally, coherence describes all properties of the correlation between physical quantities of a single wave, or between several waves or wave packets. It contains several distinct concepts, which are limit cases that never occur in reality but allow an understanding of the physics of waves, and has become a very important concept in quantum physics. In physics, coherence is an ideal property of waves that enables stationary interference. Preface to.įreebase (0.00 / 0 votes) Rate this definition:

Consistency in reasoning, or relating, so that one part of the discourse does not destroy or contradict the rest.Ĭoherence of discourse, and a direct tendency of all the parts of it to the argument in hand, are most eminently to be found in him. The texture of a discourse, by which one part follows another regularly and naturally. Why between sermons and faith should there be ordinarily that coherence, which causes have with their usual effects? It shall be no trouble to find each controversy’s resting place, and the coherence it hath with things, either on which it dependeth, or which depend on it. Connection dependency the relation of parts or things one to another. Matter is either fluid or solid words that may comprehend the middle degrees between extreme fixedness and coherency, and the most rapid intestine motion. The weight or pressure of the air will not explain, nor can be a cause of the coherence of the particles of air themselves. Samuel Johnson's Dictionary (0.00 / 0 votes) Rate this definition:ġ.That state of bodies in which their parts are joined together, from what cause soever it proceeds, so that they resist divulsion and separation nor can be separated by the same force by which they might be simply moved, or being only laid upon one another, might be parted again.

Coherence definition