Abstract

Recently much work on fibre lasers has concentrated on improving the maximum output energy and peak powers available from such systems. An important recent advance in this area has been the development of single transverse-mode, large mode area (LMA-) doped fibre¹. The LMA gives increased energy storage reduces the impact of optical nonlinearities and improves the power handling capabilities of the fibre. We have developed LMA fibre designs allowing robust, single transverse-mode laser operation with fibre Mode Field Diameters (MFDs) in excess of 30 μm, i.e around 5 times larger than conventional doped fibre designs Q-switch fibre lasers based on this fibre have yielded pulse energies in excess of 0.5 mJ. Here we present the first demonstration of the use of such fibre in a passively mode-locked soliton laser. Subpicosecond, 1 nJ soliton pulses are obtained representing more than an order of magnitude increase in pulse energy relative to conventional soliton lasers.

© 1998 IEEE