Suppression of dynamic laser speckle signals in multimode fibers of various lengths.
The effects of fiber coupling and fiber length on photocurrent fluctuations are studied when the light of a laser diode transmitted to and from a dynamic turbid medium by a step-index multimode fiber is studied. When the laser light is coupled asymmetrically, filling only the higher-order modes, the photocurrent fluctuations are suppressed significantly when fiber lengths of as much as 16 m are added between the laser and the medium. Addition of as much as 16 m of detection fiber, or any fiber in the case of symmetric light coupling, leads to much less or no suppression of the photocurrent fluctuations.
Petoukhova
Anna L
AL
Faculty of Science and Technology, Biophysical Techniques Group, University of Twente, P.O. Box 217, NL 7500 AE Enschede, The Netherlands.
Cleven
Ester
E
de Mul
Frits F M
FF
Steenbergen
Wiendelt
W