Quantum Optics
Cryogenic Nanophotonic Packaging Achieves Record Sub-1 dB Fiber Coupling Loss
Researchers demonstrate a reproducible cryogenic packaging technique coupling tapered optical fibers to nanophotonic devices with <1 dB loss per facet at ~730 nm, stable from 300 K to 30 mK. The method enables permanent, broadband interfaces compatible with etched lithium niobate on insulator wav…
Automated Optimization Achieves >60 dB Extinction in Silicon MZI Without Pre-Calibration
Researchers demonstrate over 60 dB extinction ratio in a cascaded Mach-Zehnder interferometer (MZI) on silicon photonics, using additional MZIs as tunable beamsplitters to compensate fabrication imperfections. An automated progressive optimization algorithm enables this without pre-calibration. This…
GaN Directional Couplers Enable High-Visibility Quantum Interference in Integrated Photonics
Large cross-section GaN waveguides support integrated quantum photonic circuits via directional couplers designed with beam propagation method and fabricated by ICP etching. SEM confirms high-quality facets and precise rib gaps. At 800 nm, devices exhibit single-mode operation, tunable splitting rat…