Contact

  • Academic
    hcarr@stanford.edu
    University - Student Department: Materials Science and Engineering Position: Graduate

Additional Info

  • Mail Code: 4034

All Publications

  • Very-large-scale integrated high quality factor nanoantenna pixels. Nature nanotechnology Dolia, V., Balch, H. B., Dagli, S., Abdollahramezani, S., Carr Delgado, H., Moradifar, P., Chang, K., Stiber, A., Safir, F., Lawrence, M., Hu, J., Dionne, J. A. 2024

    Abstract

    Metasurfaces precisely control the amplitude, polarization and phase of light, with applications spanning imaging, sensing, modulation and computing. Three crucial performance metrics of metasurfaces and their constituent resonators are the quality factor (Q factor), mode volume (Vm) and ability to control far-field radiation. Often, resonators face a trade-off between these parameters: a reduction in Vm leads to an equivalent reduction in Q, albeit with more control over radiation. Here we demonstrate that this perceived compromise is not inevitable: high quality factor, subwavelength Vm and controlled dipole-like radiation can be achieved simultaneously. We design high quality factor, very-large-scale-integrated silicon nanoantenna pixels (VINPix) that combine guided mode resonance waveguides with photonic crystal cavities. With optimized nanoantennas, we achieve Q factors exceeding 1,500 with Vm less than 0.1 ( λ / n air ) 3 . Each nanoantenna is individually addressable by free-space light and exhibits dipole-like scattering to the far-field. Resonator densities exceeding a million nanoantennas per cm2 can be achieved. As a proof-of-concept application, we show spectrometer-free, spatially localized, refractive-index sensing, and fabrication of an 8 mm × 8 mm VINPix array. Our platform provides a foundation for compact, densely multiplexed devices such as spatial light modulators, computational spectrometers and in situ environmental sensors.

    View details for DOI 10.1038/s41565-024-01697-z

    View details for PubMedID 38961248

    View details for PubMedCentralID 10971570

  • Toward "super-scintillation" with nanomaterials and nanophotonics. Nanophotonics Carr Delgado, H., Moradifar, P., Chinn, G., Levin, C. S., Dionne, J. A. 2024; 13 (11): 1953-1962

    Abstract

    Following the discovery of X-rays, scintillators are commonly used as high-energy radiation sensors in diagnostic medical imaging, high-energy physics, astrophysics, environmental radiation monitoring, and security inspections. Conventional scintillators face intrinsic limitations including a low extraction efficiency of scintillated light and a low emission rate, leading to efficiencies that are less than 10 % for commercial scintillators. Overcoming these limitations will require new materials including scintillating nanomaterials ("nanoscintillators"), as well as new photonic approaches that increase the efficiency of the scintillation process, increase the emission rate of materials, and control the directivity of the scintillated light. In this perspective, we describe emerging nanoscintillating materials and three nanophotonic platforms: (i) plasmonic nanoresonators, (ii) photonic crystals, and (iii) high-Q metasurfaces that could enable high performance scintillators. We further discuss how a combination of nanoscintillators and photonic structures can yield a "super scintillator" enabling ultimate spatio-temporal resolution while enabling a significant boost in the extracted scintillation emission.

    View details for DOI 10.1515/nanoph-2023-0946

    View details for PubMedID 38745841

    View details for PubMedCentralID PMC11090085

  • A thermally controlled high-Q metasurface lens APPLIED PHYSICS LETTERS Klopfer, E., Delgado, H., Dagli, S., Lawrence, M., Dionne, J. A. 2023; 122 (22)

    View details for DOI 10.1063/5.0152535

    View details for Web of Science ID 001000068400003