Signal processing applications and analysis on active optical couplers

Current passive optical devices are limited in their flexibility in that once constructed the characteristics of the device are fixed. Active optical couplers utilizing SOAs are introduced as a device which overcomes this limitation. A lattice filter structure of active two-port optical couplers is analyzed and an algorithm is developed to use an n-stage structure to approximate solutions of an nth order ordinary differential equation. Simulation results are presented with MATLAB to demonstrate the accuracy of the estimation. A four-port optical coupler is introduced. Each four-port coupler is characterized by sixteen parameters governed by ten energy constraints. Alternative, mathematically convenient representations which allow a four-port coupler to be characterized with six free parameters are presented and analyzed. Future work in developing signal processing techniques for active optical filters is discussed.