We report on the generation of optical masks that permit the spatial shaping of a laser beam so that one can selectively excite single modes of a multimode parabolic graded-index optical fiber. The amplitude masks are determined by the analytical radial function of the fiber mode in the weakly guiding approximation. Phase reversal is encoded on the transparency through a shifted-grating technique. Effective injection and propagation of a single mode in a largely multimode fiber are shown as examples.
© 1994 Optical Society of America
Original Manuscript: December 22, 1993
Published: April 1, 1994
F. Dubois, Ph. Emplit, and O. Hugon, "Selective mode excitation in graded-index multimode fiber by a computer-generated optical mask," Opt. Lett. 19, 433-435 (1994)