Upconversion presently receives much interest, mainly for the development of visible sources pumped in the near infrared. This has been realized in many crystals doped with rare-earth (RE) ions. Important objectives are obtaining room temperature cw operation and diode pumping. It is thought that optical fibers that have shown high performances in the laser domain1 can bring major improvements in the upconversion process, owing to their unique properties of light confinement over long lengths.
© 1991 Optical Society of AmericaPDF Article