2025/05/29 by Qi, Luke, Khalatpour, Ali, Herrmann, Jason +8
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Optics (physics.optics)
paper · doi:10.48550/arxiv.2505.23411
We present low-loss (<1.5%) and power-efficient Mach-Zehnder interferometers (MZIs) on thin-film lithium niobate. To accurately measure low MZI losses, we develop a self-calibrated method using tunable Sagnac loop reflectors (SLRs) to build cavities. Fabry-Pérot cavities constructed from these fabrication-tolerant SLRs achieve an intrinsic quality factor of 2 × 106. By implementing thermal isolation trenches, we also demonstrate a >10× reduction in power consumption for thermo-optic phase shifters, achieving a π-phase shift (Pπ) with just 2.5 mW. These tunable and efficient components are key for scaling up to complex photonic integrated circuits.