FIBEROPTIC 1X6 SWITCH WITH SMOOTH TRANSMISSION SPECTRUM

A multimode fibre-optic 1 x 6 switch is constructed with a large separ ation (50 mm) between the endfaces of the input and output fibre, thus reducing interference ripple in the transmission spectrum. Six fibres are arranged in a bundle symmetrically around a seventh central fibre . The bundle is cut and the endface of the central fibre is imaged by a spherical mirror on one of the six peripheral fibres. For switching to other fibres the mirror is rotated by a stepper motor. In an experi mental version of this switch, an average insertion loss of 1.6 dB was measured at lambda = 0.54 mum, which might be reduced to 0.5 dB by me ans of optical coatings.