Optics and Lasers in Engineering 41 (2004) 105–111 Reducing and eliminating induced losses during UV-laser processing of photo-hypersensitised optical fibres J. Canning*, P.-F. Hu Optical Fibre Technology Centre & Australian Photonics Cooperative Research Centre, University of Sydney, 206 National Innovation Centre, ATP, Eveleigh, NSW 1430, Sydney, Australia Received 1 March 2002; accepted 16 July 2002 Abstract Photo-hypersensitisation of optical waveguides allows significant reduction of UV-induced attenuation during subsequent photolytic writing of gratings and other components. Within phosphosilicate fibres these losses can be eliminated across the entire near UV to near IR spectrum opening up the possibility of UV-written waveguide components at any wavelength. r 2002 Elsevier Science Ltd. All rights reserved. PACS: 42.40.E; 42.81; 87.53 Keywords: Laser processing; Hypersensitisation; Fibre components; Optical waveguides; Optical glasses 1. Introduction Photolytic hypersensitisation in the presence of hydrogen, primarily by UV-laser processing, is an efficient means of enhancing waveguide photosensitivity without incurring the numerous disadvantages associated with the use of fully hydrogen- loaded waveguides during component manufacture [1–4]. Disadvantages such as hydrogen out-diffusion during component manufacture and processing is eliminated whilst the thermal stability of the induced changes is increased tremendously [2,3]. For telecommunication applications, the possibility of completely removing post- thermal annealing from the manufacturing process allows greater control over ARTICLE IN PRESS *Corresponding author. Tel.: +61-2-9351-1934; fax: +61-2-9351-1910. E-mail address: j.canning@oftc.usyd.edu.au (J. Canning). 0143-8166/02/$-see front matter r 2002 Elsevier Science Ltd. All rights reserved. PII:S0143-8166(02)00119-7