10 cm Yb3+ DFB fibre laser with permanent phase shifted grating

Abstract
A diode pumped Yb3+ DFB fibre laser comprising a single 10 cm Bragg grating with a permanent π/2 phase shift has been demonstrated. The DFB laser operates at 1047 nm with an in-fibre pump threshold < 230 µW and a 44% one-way slope efficiency. DFB operation was demonstrated using the heat-scan technique.