Tunable Integrated Optical Ringresonator

Optical fibre systems, especially coherent optical fibre communications systems require wavelength stabilization. This is usually being done by using stabilization circuits with Fabry-Perot-resonators /1/. However, application of Fabry-Perot-resonators for this purpose has two drawbacks: first strong wavelength dependent reflections occur and second it is not an integrated optic solution. The first drawback can be handled by using ringresonators. A fibre optic solution was recently described by Bachus et al. /2/. An integrated optical ringresonator was also realized recently using silver ion exchange in glass /3/. The disadvantage of both devices is that alignment and tuning are almost impossible. It follows from this considerations that an integrated optical ringresonator is required which is adjustable and tunable.