High Extinction Ratio In-Fibre Polarisers by Exploiting Tilted Fibre Bragg Grating Structures for Single-Polarisation High-Power Fibre Lasers and Amplifiers

This report results from a contract tasking Aston University as follows: This is a follow-on proposal to our previous project of High extinction ratio in-fibre polarisers by exploiting tilted fibre Bragg grating structures for single-polarisation high-power fibre lasers and amplifiers awarded by EOARD (FA8655-06-1-3068) in September 2006. The scientific findings from this project have given rise to new scope for further R&D on high-function in-fibre polarisation devices in speciality fibres. These new devices may have the potential for implementing novel in-fibre optical isolators and polarisation controllers to be used for coherent beam combining fibre laser and amplifier systems. In order to facilitate the two new AFRL projects - (1) In-fibre optical isolator for high-power operation and (2) Self-organisation for polarisation and coherent beam combination of fibre lasers, proposed respectively by Dr. Gerry Moore and Dr. Tim Newell of AFRL, we propose here to develop high-function in-fibre polarisation devices by exploiting tilted grating structures in high birefringent (hi-bi) and Yb-doped fibres, including both conventional and AFRL project specific types. The specially designed, fabricated and optimised tilted grating devices will be delivered to AFRL for evaluation and finally for integration to their high-power operation in-fibre optical isolator and coherent beam combining systems.
The original document contains color images.