arXiv subjects

Sydney Mason

Publications and source records attributed to Sydney Mason.

5 recordsLinked to original sources

arXiv2026

Inverse design for scalable photonic systems

Over the past two decades, photonic inverse design has emerged as a powerful approach to implement photonic devices with improved performance, or realize new functionalities. While the efforts over the first decade focused on proof of concept devices designed and fabricated in university labs, the focus over the past 5-10 years has shifted towards implementation of scalable photonic systems. This article reviews this recent progress, challenges and new directions in photonics inverse design, thus providing a complementary and updated review of the field. We focus on large scale three dimensional photonic inverse design, including metasurfaces, translation of inverse design to commercial foundries and practical silicon photonics, application of photonic inverse design to different materials systems, wavelengths, and optical effects, and finally new directions such as inverse design of quantum systems.

physics.optics↗

arXiv2025

High-Performance Wavelength Division Multiplexers Enabled by Co-Optimized Inverse Design

Wavelength division multiplexers are fundamental to the functioning and performance of integrated photonic circuits, with applications ranging from optical interconnects to sensing and quantum technologies. Current solutions are limited by trade-offs between channel spacing, crosstalk, insertion loss, and device footprint. Here, we develop a novel design approach that co-optimizes inverse-designed wavelength division multiplexers and distributed Bragg gratings to achieve ultra-low crosstalk without compromising insertion loss. We experimentally demonstrate less than -40 dB crosstalk for wavelength channel spacing of 15 nm in foundry-compatible silicon and silicon nitride devices across the telecommunications C- and L-bands. Our design process is highly adaptable, allowing for seamless scaling to a greater number of output channels, different spectral windows, and easy translation across various material platforms.

physics.optics↗

arXiv2023

Metasurface-controlled holographic microcavities

Optical microcavities confine light to wavelength-scale volumes and are a key component for manipulating and enhancing the interaction of light, vacuum states, and matter. Current microcavities are constrained to a small number of spatial mode profiles. Imaging cavities can accommodate complicated modes but require an externally pre-shaped input. Here, we experimentally demonstrate a visible-wavelength, metasurface-based, holographic microcavity that overcomes these limitations. The micron-scale metasurface cavity fulfills the round-trip condition for a designed mode with a complex-shaped intensity profile and thus selectively enhances light that couples to this mode, achieving a spectral bandwidth of 0.8 nm. By imaging the intracavity mode, we show that the holographic mode changes quickly with the cavity length, and the cavity displays the desired spatial mode profile only close to the design cavity length. When placing a metasurface on a distributed Bragg reflector and realizing steep phase gradients, the correct choice of the reflector's top layer material can boost metasurface performance considerably. The applied forward-design method is readily transferable to other spectral regimes and mode profiles.

physics.optics↗

arXiv2023

Hybrid silicon-organic Huygens' metasurface for phase modulation

Spatial light modulators have desirable applications in sensing and free space communication because they create an interface between the optical and electronic realms. Electro-optic modulators allow for high-speed intensity manipulation of an electromagnetic wavefront. However, most surfaces of this sort pose limitations due to their ability to modulate intensity rather than phase. Here we investigate an electro-optic modulator formed from a silicon-organic Huygens' metasurface. In a simulation-based study, we discover a metasurface design immersed in high-performance electro-optic molecules that can achieve near-full resonant transmission with phase coverage over the full 2$π$ range. Through the electro-optic effect, we show 140$^\circ$ (0.79$π$) modulation over a range of -100 to 100 V at 1330 nm while maintaining near-constant transmitted field intensity (between 0.66 and 0.8). These results potentiate the fabrication of a high-speed spatial light modulator with the resolved parameters.

physics.optics↗

arXiv2021

Gigahertz free-space electro-optic modulators based on Mie resonances

Electro-optic modulators from non-linear $χ^{(2)}$ materials are essential for sensing, metrology and telecommunications because they link the optical domain with the microwave domain. At present, most geometries are suited for fiber applications. In contrast, architectures that modulate directly free-space light at gigahertz (GHz) speeds have remained very challenging, despite their dire need for active free-space optics, in diffractive computing or for optoelectronic feedback to free-space emitters. They are typically bulky or suffer from much reduced interaction lengths. Here, we employ an ultrathin array of sub-wavelength Mie resonators that support quasi bound states in the continuum (BIC) as a key mechanism to demonstrate electro-optic modulation of free-space light with high efficiency at GHz speeds. Our geometry relies on hybrid silicon-organic nanostructures that feature low loss ($Q = $ 550 at $λ_{res} = 1594$ nm) while being integrated with GHz-compatible coplanar waveguides. We maximize the electro-optic effect by using high-performance electro-optic molecules (whose electro-optic tensor we engineer in-device to exploit $r_{33} = 100$ pm/V) and by nanoscale optimization of the optical modes. We demonstrate both DC tuning and high speed modulation up to 5~GHz ($f_{EO,-3 dB} =3$ GHz) and shift the resonant frequency of the quasi-BIC by $Δλ_{res}=$11 nm, surpassing its linewidth. We contrast the properties of quasi-BIC modulators by studying also guided mode resonances that we tune by $Δλ_{res}=$20 nm. Our approach showcases the potential for ultrathin GHz-speed free-space electro-optic modulators.

physics.optics↗