Abstract: An apparatus for performing mode scrambling in a multimode optical fibre 1 comprises an electromechanical transducer 3 and a signal generator 9. A portion of the fibre 1, which is in the form of a loop 5, is arranged with its ends 6 fixed to the transducer 3, but with the remainder of the portion being left free to vibrate. The signal generator 9 drives the transducer 3 so as to form a succession of bends of differing bend radii in the portion of the fibre as a beam of electromagnetic radiation travels through the fibre, thereby “scrambling” the beam as it travels through the fibre.

Abstract: An apparatus for performing mode scrambling in a multimode optical fibre 1 comprises an electromechanical transducer 3 and a signal generator 9. A portion of the fibre 1, which is in the form of a loop 5, is arranged with its ends 6 fixed to the transducer 3, but with the remainder of the portion being left free to vibrate. The signal generator 9 drives the transducer 3 so as to form a succession of bends of differing bend radii in the portion of the fibre as a beam of electromagnetic radiation travels through the fibre, thereby “scrambling” the beam as it travels through the fibre.

Abstract: Apparatus for use in applying particles to an external layer of uncured resin material of a coating of an optical fibre unit with at least one optical fibre, said apparatus including means (50) defining an axially extending through-passage (52) through which, in use, such an optical fibre unit is passed, said passage defining means having an inlet (62) for admitting fluidized particles into said through-passage, and said through-passage being provided with means (64) for generating turbulence in such fluidized particles in said through-passage.