Speckle and Modal Noise Techniques for Coupling of Light between Optical Graded Index Fibers

Abstract

The speckle pattern observed in multimode fiber, is closely related to the modal noise. In this paper we study the intensity distribution of the speckle patterns over the output surface of a multimode graded index fiber as a function of the incident beam alignement over the input surface of the fiber. Three kinds of incident beam misalignment speckle patterns were registrated photographically. Our results shown that the aforementioned distribution is highly dependent on the incident beam alignement.

GHz Analog Transmission on a Single Mode Optical Fibre Link using a Laser with Multimode Pigtail

“…Reference [8] gives pictures of typical speckle patterns possible in a multimode fibre with a laser light. The micro manipulator was adjusted in the X, Y, Z directions to couple a portion of light out of the speckles from the laser's multimode fibre pigtail into the single mode (SM) fibre.…”