Abstract

Over the past few years there has been great progress in the field of fiber lasers, particularly in the areas of high output power generation of shorter output wavelengths via upconversion. Single mode output powers in excess of up to 5 W have been reported for a neodymium doped fiber laser, with powers up to 100 W reported in multiple-fiber bundles.¹ Upconversion lasting in fibers based on low-phonon energy glasses has yielded a wide variety of output wavelengths in the visible and infrared, but up till now efficiency and output powers have been limited. In this paper we report the highest power, highest efficiency upconversion laser to date, with output powers of up to 2 W at 810 nm. The laser is based on thulium doped fluorozirconate fiber pumped via two-photon absorption of light at 1064 nm from a cw Nd:YAG laser, following a scheme first demonstrated by Komukai, et al.,² to obtain powers up to 1 W at 1470 nm, and with which we have previously obtained upconversion powers up to 1.2 W.³

© 1994 Optical Society of America