Integrated Photonics Characterization And Design For Optical Quantum Logic

Microring resonators with Spontaneous Four-Wave Mixing (SFWM) have been used in literature to produce entangled photons of specific wavelengths. By routing these photons in a phase shifter array, a Bell state can be created, a building block for quantum logic. To determine the design parameters of a microring resonator best-suited for optimizing the effect of \chi^3 nonlinearity, 96 microring resonators with varying coupling angle, coupling gap, radius, waveguide width, and PIN diode contacts were measured and characterized to find the quality factors of each device. Comparing the calculated quality factors versus each varied parameter, trends in these parameter spaces then informed design optimization with Lumerical Finite Difference Time Domain (FDTD) software to produce microrings with high tolerance Free Spectral Ranges (FSRs) for the intent of precise wavelengths of entangled photon pairs. With progress in SFWM still underway, a 3x3 phase shifter network composed of Mach-Zehnder Interferometers (MZIs) is in the early stages of testing with a tunable source at 810 nm with the intention of routing incoming idler photons in each photon pair to form a position-encoded Bell state with the signal photons measured for Bell state verification.