Fiber Optical Coupling with Engineered Scattering Elements

Optical interconnects using a silicon-on-insulator integrated circuit platform have become the basis for many modern communications platforms. One limiting factor in interconnect technology is creating a consistent, reliable method for measuring the amount of coupled light from optical fibers into waveguides in a photonic integrated circuit. Monitoring the coupling efficiency before, during, and after would be the ideal scenario for fiber bonding. Using a foundry compatible engineered scattering element developed by our lab, we have been able to monitor the degree of fiber alignment by recording the relative power scattered by the engineered element. Recorded powers are then compiled to generate a heat map of the optimal fiber position for coupling. These scattering elements are also polarization sensitive, thus allowing for the fast axis of polarization maintaining fibers to be monitored and optimized for coupling.