Analog Integrated Circuit Design for Photonic Drift Compensation

Photonics systems deployed across different application domains require long-term operational stability. In optical communication, wavelength-division multiplexed (WDM) channels must remain precisely aligned to their designated wavelengths, and coherent optical transceivers demand stabilized phase and amplitude control. Large-scale switching networks for programmable photonics rely on accurate tuning of individual switching elements, while optical phased arrays necessitate precise phase control of each emitter. 

However, environmental fluctuations and material changes can induce drift in the optical characteristics of photonic components, resulting in wavelength misalignments, phase errors, or signal degradation. To counteract these effects, feedback control loops can be integrated into programmable photonic circuits. These loops utilize monitoring signals obtained by tapping a small fraction of optical power at strategic locations within the photonic circuit, detected via integrated or external photodetectors. The feedback mechanism itself may be implemented in software, on an FPGA, or through fully analog on-chip circuitry. 

This internship offers the opportunity to investigate automated drift compensation circuits for stabilizing optical wavelength, phase, and amplitude in programmable photonic components such as Mach-Zehnder interferometers, tunable filters, and phase shifters. Working in close collaboration with a photonics engineer, the student will explore and design analog feedback loop IC architectures. The internship student will be in charge of the conceptualization, design, and layout of stabilization feedback circuits to be fabricated on a 200mm CMOS-photonics integration platform.