Linearly polarized all-fiber laser using a short section of highly polarizing microstructured fiber

A linearly polarized all‐fiber erbium laser is presented in this work. The polarization selective element consists on a piece of a single‐mode, polarizing microstructured fiber, which is placed within the laser cavity. The microstructured fiber shows a regular lattice of air‐holes, in which four holes next to the core were enlarged. This fiber shows a polarization dependent loss of 16 dB/m around 1550 nm. The laser cavity presents different losses for each polarization and, as a consequence, a highly polarized emission is obtained. The polarization ratio of the emitted power was in excess of 20 dB. (© 2007 by Astro Ltd., Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)