Long-term stability of fibre-optic transmission for multi-object spectroscopy

Abstract

We present an analysis of the long-term stability of fibre-optic transmission properties for fibre optics in astronomy. Data from six years of operation of the AAOmega multi-object spectrograph at the Anglo-Australian Telescope is presented. We find no evidence for significant degradation in the bulk transmission properties of the 38 m optical fibre train. Significant losses (<20% relative, 4% absolute) are identified and associated with the end termination of the optical fibres in the focal plane. Improved monitoring and maintenance can rectify the majority of this performance degradation.