A new design approach for fiber DFB lasers with improved efficiency

The standard distributed feedback (DFB) laser optimization method is critically investigated and a new design approach based on the effective cavity length is presented. By applying this method in an erbium-ytterbium co-doped fiber, the pump-to-signal conversion ratio is increased by 40% for the same total device length and pumping conditions. The laser with the proposed design is produced and the theoretical results are verified by the experimental work.