Published online by Cambridge University Press: 25 April 2016
Work on the development and use of optical fibres as light guides in astronomical spectroscopy has been underway at the AAO for over a year now. The fibres used are step-index polymer-clad silica with a core size of 200 microns giving an aperture size of 1.3 arcsec at the AAT f/8 focus. They are optimised for data transmission with losses below 5dB/km at a wavelength of 800 nm. The blue transmission is somewhat lower, typically 500dB/km at 300nm and 90dB/km at 400nm but over the short 2m length used these attenuations give transmissions of 79% and 96% respectively.