Karina Kiely 2002

Part of the system for producing the gain flattening filters

My honours project was based at the fibre optic components company, JDS Uniphase. At the time, the main task of the Sydney division of JDS Uniphase was to manufacture gain flattening filters for long haul, undersea fibre cables.  

A gain flattening filter is a type of fibre Bragg grating, or refractive index modulation along the fibre core.  By attenuating some wavelengths of the light travelling within the fibre cable more than others, the filter makes the spectral response of an optical amplifier output more uniform. An optical amplifier, together with a gain flattening filter, is required approximately every 80km to 100km in undersea fibre networks so that incoming signals reach their destinations.  The aim of my project was to design an automated solution to the manufacture of gain flattening filters so as to increase production yield by eliminating human error.

I became familiar with the manufacturing process in detail and undertook research to determine the individual and combined effects of many input parameters on the final spectral response. The outcome of this research was an automatic algorithm for determining the change in input parameters required to produce a satisfactory device. The algorithm was tested and then implemented into the production system using LabView. This method was proven to be more accurate than current technology and achieved the goal of increased production yield.