SPECKLE PATTERN

In optical systems, a field - intensity pattern produced by the mutual interference of partially coherent beams that are subject to minute temporal and spatial fluctuations. ( 188 ) Note: In a multimode fiber, a speckle pattern results from a superposition of mode field patterns. If the relative modal group velocities change with time , the speckle pattern will also change with time. If differential mode attenuation occurs, modal noise results.