Optically active erbium-doped waveguides fabricated using a single-sol-gel-deposition technique

We present the results of optical-characterization experiments conducted on optically active erbium-doped waveguides. Using selected characterization results presented in this paper and a simple analysis, the device operation is evaluated. Each of the core and the cladding layers were individually fabricated using a single sol-gel deposition. These are, to the best of our knowledge, the first optically active waveguides to be fabricated in such a way. Characterization results include gain, fluorescence-lifetime, waveguide-loss, polarization-dependent-loss (PDL), and erbium-absorption measurements. Relative gains of over 1 dB·cm^-1 were measured. Fluorescence lifetimes of the ⁴I₁₃2/ → ⁴I₁₅2/ transition as high as 5.6 ms were observed. Waveguide losses as low as 0.13 dB·cm^-1 were measured.