RESUMO
Ti4+-diffused Zr4+/Er3+-codoped LiNbO3 strip waveguide was fabricated on an X-cut LiNbO3 substrate by thermal diffusion in sequence of Er3+, Zr4+ and Ti4+. Secondary ion mass spectrometry study shows that the Ti4+ ions follow a sum of two error functions in the width direction and a Gauss function in the depth direction of the waveguide. Both Er3+ and Zr4+ profiles follow the desired Gauss function, and entirely cover the Ti4+ profile. Optical study shows that the waveguide is TE or TM single mode at 1.5 µm wavelength, and has a loss of 0.3 (0.5) dB/cm for the TM (TE) mode. In the case of 980 nm pumping, the waveguide shows stable 1547 nm signal output under high-power pumping without optical damage observed, and a net gain of 1.1 dB/cm is obtained for the available pump power of 120 mW.