All-fibre narrowband reflection gratings at 1500 nm

The first demonstration of reflection gratings at around 1500 nm written into germanosilicate fibres using an ultraviolet laser is reported. Grating reflection coefficients up to 10% with linewidths around 1nm have been observed. By using one of these gratings, narrow linewidth operation of a 1500 nm Er3+ doped fibre laser has been achieved.