Design Of Semiconductor Micro-cavity Narrow Bandwidth Filter

Integration is the developing direction of optoelectronic devices, and the development of DWDM technology also calls for narrow bandwidth filter. With the development of these two technologies, semiconductor micro-cavity narrow bandwidth filter is in great need. The micro-ring narrow bandwidth filter is one kind of semiconductor micro-cavity narrow bandwidth filter.This thesis introduces the development of micro-ring filter and its application, and analyses the scheme of other micro-ring filters.To use micro-ring to form narrow bandwidth filter, we should first get to know the scheme of micro-ring, and how light resonate in it. Therefore, based on Finite-Difference Time-Domain method, passive micro-ring is firstly studied. The process of coupling, transmitting and resonating of light field in passive micro-ring is simulated. By injecting an ultra-short Gaussian pulse, and analyzing the input frequency spectrum, the spectrum of the Gaussian pulse coupled to the micro-ring, the throughput port frequency spectrum, and the drop port frequency spectrum, we get the spectrum characteristics of coupling coefficient, and the curve of the micro-ring's transmission characteristics in throughput port and drop port. Then, based on Finite-Difference Time-Domain method, active micro-ring is also studied. The process of coupling, transmitting and resonating of light field in active micro-ring is simulated. By injecting an ultra-short Gaussian pulse, and analyzing the input frequency spectrum, the throughput port frequency spectrum, and the drop port frequency spectrum, we get the spectrum characteristics of coupling coefficient, and the curve of the micro-ring's transmission characteristics in throughput port and drop port.After getting to know the scheme of micro-ring, in order to realize narrow bandwidth filter, the transfer function of M×N micro-ring array filter is studied by using transfer function method. By comparing and analyzing we get to know the proper row for the micro-ring filter that can be used later. Then two methods are introduced to narrower the bandwidth of the filter: One is to perfect the coupling coefficient. By making the coupling gauss distribution and maximally flat distribution, the bandwidth can be greatly narrowred. The other is to introduce gain to the micro-ring. In the FDTD method we can see that micro-ring with gain has narrowed bandwidth. Therefore, under the condition that coupling coefficient has been perfected, gain index is introduced, and micro-ring bandwidth can be reduced to pm.