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Using a femtosecond laser writing technique, we fabricate and characterise three-waveguide digital adiabatic passage devices, with the central waveguide digitised into five discrete waveguidelets. Strongly asymmetric behaviour was observed, devices operated with high fidelity in the counter-intuitive scheme while strongly suppressing transmission in the intuitive. The low differential loss of the digital adiabatic passage designs potentially offers additional functionality for adiabatic passage based devices. These devices operate with a high contrast (>90%) over a 60 nm bandwidth, centered at ∼ 823 nm.
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http://dx.doi.org/10.1364/OE.25.002552 | DOI Listing |
IUCrJ
September 2025
Institut de Biologie Structurale, 38000 Grenoble, France.
Time-resolved neutron scattering has been used to study dynamically polarized protons in tyrosyl-doped bovine liver catalase. While the evolution of proton polarization and its inversion by the method of adiabatic fast passage (AFP) in a standard dynamic nuclear polarization (DNP) system with organic Cr(V) complexes can be well modelled and understood, the experiments with tyrosyl-doped catalase lead us into the world of extremely dilute paramagnets with only about 10 unpaired electrons per cm. In this regime, the strength of DNP is comparable to the drift of proton polarization towards its thermal equilibrium of P = 0.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou Magnetic Resonance Center, Lanzhou University, Lanzhou, Gansu 730000, China.
Further advancement in the research area of covalent organic frameworks (COFs) is in urgent need of structural information with high accuracy. The bottleneck in characterization is the lack of effective strategies to resolve the complex features (e.g.
View Article and Find Full Text PDFJ Chem Phys
July 2025
Center for Quantum and Topological Systems, New York University Abu Dhabi, P.O. Box, 129188 Abu Dhabi, United Arab Emirates.
Dynamic Nuclear Polarization (DNP) is transforming nuclear magnetic resonance and MRI by significantly enhancing sensitivity through the transfer of polarization from electron spins to nuclear spins via microwave irradiation. However, the use of monochromatic continuous-wave irradiation limits the efficiency of DNP for systems with heterogeneous, broad electron paramagnetic resonance lines. Broadband techniques such as chirp irradiation offer a potential solution, particularly for Solid Effect (SE) DNP in such cases.
View Article and Find Full Text PDFThe generation and dynamic control of the spatial mode of the dark-state polarization using electromagnetically induced transparency are theoretically investigated. We demonstrate that a combination of synthetic scalar and vector potentials can be employed to engineer discrete spatial modes of the dark-state polariton, enabling quantum interference among these modes. We verify this concept by showing the Rabi oscillation between two spatial modes and stimulated Raman adiabatic passage among Λ-type three modes.
View Article and Find Full Text PDFLithium niobate on insulator (LNOI) is a promising platform for photonic integrated circuits (PICs), and 3-dB power splitters are the most essential building blocks in PICs. In this Letter, we propose and demonstrate a broadband, fabrication-tolerant 3-dB power splitter based on the photonic bound state in the continuum (BIC) and using a spatial adiabatic passage structure on a polymer-loaded LNOI platform. The simulation results show that the proposed device can achieve a splitting ratio of 50%:50% with an excellent operating bandwidth of 180 nm (from 1450 nm to 1630 nm).
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