There is a long-standing critical bottleneck in astronomy, which limits the possibility of observations of the early Universe and starlight from distant galaxies. The main restrictions are imposed by bright infrared night sky formed by a large number of very narrow hydroxyl emission lights. One of the solutions for filtering of unwanted atmospheric lines is to use multichannel fibre Bragg gratings (FBGs) with suppression factors of 20-30 dB over the spectral window of hundreds nm. The main goal of the proposed PhD research is to develop novel approaches to fabrication of such FBGs based on a combination of original and new modelling methods and the advanced fast feedback fibre grating writing technique, recently proposed at Aston University. The PhD student will be involved in design and fabrication of advanced FBGs with application in astrophysics and other relevant areas. The second goal of the project is to study a new complimentary approach - writing gratings in multi-core fibres for use in photonics lanterns in astrophysics instrumentation. This technology has high independent value for sensing and medical and healthcare applications.