Two or more wave sources are said to be coherent sources if the phase difference between a pair of points, one in each source, remains constant.
Coherent, adj., → coherence.
nur-e hamdus (#)
Fr.: lumière cohérente
Light waves that have the same wavelength and possess a fixed phase relationship, as in a laser.
Fr.: optique cohérente
A branch of optics that uses coherent radiation to produce holographic three-dimensional images of objects.
Fr.: diffusion cohérente
A scattering process in which the scattered radiation bears the same frequency and phase as the incident radiation.
Fr.: source cohérente
One of two light beams derived from the same source in → interference experiments. It is impossible to obtain interference from two separate sources because their → wavefronts do not have a constant → phase difference. In → Young's experiment, → Fresnel's biprism, → Fresnel's mirrors, and → Lloyd's mirror the two sources always have a point-to-point correspondence of phase, since they are both derived from the same source.
mowjhâ-ye nâhamdus (#)
Fr.: ondes incohérentes
The lack of a fixed phase relationship between two or more waves. → coherent.
tâbeš-e nâhamdus (#)
Fr.: rayonnement incohrént
Radiation having waves that are out of phase in space and/or time; radiation which is not → coherent.
Fr.: diffusion incohérente
The absorption of a photon and its re-emission at a different frequency (in the observer's frame of reference) by scattering atoms.