Research On Double-slot Microring Resonator All Optical Buffer And Tuning Technology

In order to achieve high efficiency of the switching nodes in the network, multiple signal inputs have to be accessed, and properly arrangement for each signal are required to acquire smooth outputs, optical buffers can significantly benefit this process. Tunable optical buffer can provide controllable delay for optical packets without converting to electrical signals and replace the traditional store-and-forward packet switching schemes. Yet optical buffers to date are still too impractical for commercial use and therefore requires further study.This thesis considers the optical microring resonator with relatively simple structure as the basic unit of the tunable optical buffer. By cascading multiple resonators to achieve a greater bandwidth and higher delay. For highly integration, it needs to be considered that how to reduce the radius of microring while maintaining the signal quality simultaneously. Considering that common strip waveguide with strong bending have large loss and high-order dispersion, we have modified the waveguide structure. Special horizontal double-slot waveguide structure is used to improve light confinement and its dispersion tailorability can be used to minimize the high-order dispersion and keep the signal quality through structure optimization.First, we described the delay property and tuning principles of single and multiple microrings. On this basis, a horizontal double-slot waveguide is proposed and the influence of each structure parameters to high-order dispersion are simulated. The simulation results are discussed and waveguide structure for optical buffer is designed and optimized. Then the cascaded multiple racetrack microring resonators basing on the Vernier effect are studied. We performed device design and optimized the total delay spectrum and finally obtain the specific parameters for each microring resonators.Results of this thesis show that the optical buffer scheme we proposed present low dispersion and high delay flattened in broadband communication spectrum. A optical buffer with broad bandwidth and high average delay can be realized with multiple microring resonators, the dispersion is low and the footprint is small enough which will benefit the integration. In the case of size on chip allows, the number of microrings can be increased to improve the delay-bandwidth product. This thesis can provide a support for the structure designing of larger-scale optical buffers.