We have developed planar waveguides with net gain in erbium-doped zirconia. Ion-beam sputtering was used to deposit amorphous high-refractive-index zirconia films, which were fabricated into single-mode waveguides. By adjusting oxygen flow rates while sputtering, and annealing the films after deposition, waveguide losses were reduced to 0.45 dB/cm at 1534 nm. Erbium in the zirconia, added by co-sputtering, had a wide, 54-nm full-width at half maximum emission band centered at 1538 nm, which offers potential advantages for wideband amplification in wavelength division multiplexing systems. When pumped with 36 mW at 980 nm, a 6.5 cm long, 8.8 × 1019 cm-3 doped waveguide produced 2.95 dB of optical amplification at 1534 nm. This was enough to overcome the waveguide loss and produce a small amount of net gain. With a higher pump power, substantial net gain appeared to be possible. These results show that wide-bandwidth erbium-doped optical amplifiers should be possible in zirconia.
Bibliographical noteFunding Information:
Manuscript received March 22, 2002; revised September 26, 2002. This work was supported in part by the Defence Advanced Research Projects Agency and by the Army Research Laboratory. R. Schermer, W. Berglund, and A. Gopinath are with the Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 USA (e-mail: firstname.lastname@example.org). C. Ford and R. Ramberg are with Honeywell, Minneapolis, MN 55455 USA. Digital Object Identifier 10.1109/JQE.2002.806163
Copyright 2004 Elsevier Science B.V., Amsterdam. All rights reserved.
- Optical amplifiers
- Optical films
- Optical materials
- Optical planar waveguides
- Zirconium compounds