1Physics. Designating or relating to lasers in which there is a single pattern of vibration of the electromagnetic field within the laser cavity.
2Telecommunications. Designating or relating to light transmission through optical fibres in which light waves follow a single propagation path.
monomode fibrenoun an optical fibre which operates in a monomode manner as a result of the similarity between its internal diameter and the wavelength of the light it carries..
Origin
1960s; earliest use found in IEEE Journal Quantum Electronics. From mono- + mode.