Liao Duan

Major: Computer Engineering
Mentors: Trevor Steiner, Professor Galan Moody

Measurements Of Algaas Phontonic Components

Chip-scale quantum photonic circuits on the aluminum gallium arsenide (AlGaAs) photonic platform require low-loss photonic elements such as waveguide crossers where two perpendicular optical waveguides can be crossed with little to no loss. Inevitably, by introducing a crosser into a waveguide, some of the light is lost via scattering into the perpendicular waveguide. The goal of this research project is to measure the efficiency of two types of crossers via two measurement techniques many crossers in a series and crossers within ring resonators. To test the hypothesis, we first measured the transmission through an increasing number of crossers in a line. As the number of crossings in the line increased, the transmitted power decreased linearly, as expected. We also tested with the crossers inside of the rings and did data analysis to estimate the power loss per unit length for the rings. Our finding supports the conclusion that the simpler waveguide crosser design is less sensitive to fabrication and therefore has better performance than the more complex crosser design. The results of the two techniques are not identical, so further testing is necessary to determine the true loss and necessary design changes. Overall, maintaining loss below 1dB/crosser is important for a quantum photonic circuit fabricated in a single layer and beneficial in maximizing the efficiency of the circuit.