Christian Lerminiaux

1.7 μm excited state absorption measurement in erbium‐doped glasses

We have measured, for the first time, the complete 1.7µm excited state absorption spectrum in erbium doped glasses. The spectrum is obtained by measuring the gain of an erbium doped waveguide in the 1400-1800 nm region. Using the measured spectra, we estimate the 1.5µm uniform upconversion rate by calculating the spectral overlap between the 1.5µm emission and 1.7µm ESA cross sections. The technique is applied to erbium-doped, ion-exchangeable silicate glasses, yielding upconversion constants in the range of 1-10 x 10 -18 cm 3 /s.

1.7 µm Excited State Absorption Measurement in Erbium-doped Silicate Glasses

Planar erbium doped waveguide amplifiers are important components in the development of integrated optical communication circuits at 1.5 μm. Such devices must achieve high gains in short lengths and thus require high erbium concentrations (>1019 cm−3). At these doping levels, however, the amplifier gain and efficiency are degraded by ion-ion interactions in the form of uniform and clustered upconversion [1], Upconversion is a problem in erbium-doped glasses because the 4I13/2→4/15/2 emission and 4I13/2→4I9/2 ESA transitions overlap. Therefore, it is of fundamental interest to measure the ESA spectrum. Wyatt [2] measured the tail of this spectrum to demonstrate that absorption of 1.55 μm photons from the 4I13/2 level could not occur. We have measured, for the first time, the full 1.7 μm ESA spectrum in erbium-doped glasses and used it to estimate the uniform upconversion rate. The silicate glasses studied are suitable for the development of ion-exchanged waveguide amplifiers at 1.5 μm.

Ion-Exchanged Waveguide Amplifier in Erbium-Doped Glass for Broad-band Communications

We discuss the fabrication, characterisation and modelling of planar erbium-doped amplifiers realised as ion-exchanged waveguides in glass.