All-fibre frequency conversion in long periodically poled silica fibres

Efficient all-fibre frequency doubling of 1.5mm pulsed fibre laser has been demonstrated. 3.6mW of second-harmonic light in fundamental mode was produced by quasiphase- matching in a 11.5cm long periodically poled germanosilicate fibre. The c(2)-grating was fabricated by continuous periodic-UV-erasure. © 2005 Optical Society of America.