Yb:LiNbO3 Annealed/Proton-Exchanged Waveguide Lasers Pumped by InGaAs Laser Diode at 980 nm Wavelength

Abstract

Various waveguide lasers in rare-earth-doped LiNbO3 have been studied, and an Yb:LiNbO3 annealed/proton-exchanged (APE) waveguide laser pumped at a 918 nm wavelength has been reported recently. In this paper, an Yb:LiNbO3 APE waveguide laser pumped at a 980 nm wavelength is proposed and demonstrated. Pumping at 980 nm allows the use of a commercially available InGaAs laser diode for a pump source instead of a Ti:Al2O3 laser used in the previous work. The longer pump wavelength is favorable to avoid photorefractive damage. A prototype device was designed, fabricated and tested. Laser oscillation was achieved at 1061 nm wavelength with a threshold pump power of 30 mW. An output power of 4.3 mW was obtained, which was three-orders of magnitude larger than that obtained in the previous work.