Research

Papers focusing on optical coherence control, measurement, and plasmonic interferometry with spatial coherence modulation.

Nature Photonics, 2016 – Measuring Subwavelength Spatial Coherence with Plasmonic Interferometry

This study introduces a novel plasmonic interferometric method capable of measuring subwavelength spatial coherence lengths, a fundamental challenge in optics. Using plasmonic nanostructures, we achieved coherence length measurements as small as 330 nm for a 500 nm incident wavelength, surpassing traditional interferometric techniques. We demonstrated a prototype of an integrated “coherence meter.” This breakthrough enables new applications in super-resolution imaging, optical coherence tomography, and nanophotonic device characterization.

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Science Advances, 2017 – Strong Amplitude and Phase Modulation of Optical Spatial Coherence with SPPs

We demonstrated how surface plasmon polaritons (SPPs) can actively modulate the spatial coherence of light, achieving continuous control over coherence from fully incoherent (0%) to highly coherent (80%) states. This work provides a foundation for dynamic coherence shaping in imaging, beam shaping, and quantum optics applications. The ability to engineer coherence at the nanoscale opens avenues for compact, tunable photonic systems.

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Scientific Reports, 2016 – Nanoscale Optical Interferometry with Incoherent Light

We challenged the conventional assumption that coherent light is required for optical interferometry, demonstrating that plasmonic interferometers can extract coherence information even from incoherent light sources. This study expands the applicability of plasmonic sensors beyond traditional coherent sources, enabling new high-sensitivity optical sensors, real-time biosensing, and enhanced photonic integration.

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Studies on higher-order plasmonic modes, spectral modulation, and refractive index sensing using passive and active plasmonic interferometers.

Optics Express, 2016 – Higher-Order SPP Contributions to Passive and Active Plasmonic Interferometry

This paper systematically investigated higher-order surface plasmon polariton (SPP) contributions in plasmonic interferometry and demonstrated how odd-order SPP modes can be selectively suppressed by controlling the coherence of the incident light. This work refines our understanding of plasmonic coherence control and provides pathways for tunable optical modulation, enhanced biosensing, and quantum plasmonic applications.

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Journal of Applied Physics, 2016 – A Spectroscopic Refractometer Based on Plasmonic Interferometry

We developed a plasmonic refractometer that enables high-precision refractive index measurements of various materials, including biological fluids and noble metals. This technique eliminates the need for bulky prism-based coupling or grating-based SPR systems, providing a compact and tunable solution for lab-on-a-chip sensing, environmental monitoring, and pharmaceutical analysis.

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Work focusing on biosensors, biomarker detection, and plasmonic-based biochemical analysis.

Biosensors, 2021 – Plasmonic Interferometers as TREM2 Sensors for Alzheimer’s Disease

We developed a plasmonic biosensor capable of detecting Triggering Receptor Expressed on Myeloid Cells 2 (TREM2), a key biomarker for Alzheimer’s disease. Our sensor leverages high-specificity surface functionalization to achieve label-free, real-time biomolecular detection, offering a promising alternative to traditional ELISA-based assays for early-stage neurodegenerative disease diagnostics.

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Optical Materials Express, 2015 – Circular Slit-Groove Plasmonic Interferometers for Biochemical Sensing

This paper introduces a circular slit-groove plasmonic interferometer, an innovative sensing platform that enhances optical transmission, increases sensitivity, and achieves polarization-independent operation. Compared to traditional plasmonic sensors, this new design provides 7× higher sensitivity, making it suitable for high-throughput multiplexed biosensing applications.

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Nanophotonics, 2014 – A ‘Plasmonic Cuvette’: Dye Chemistry Coupled to Plasmonic Interferometry for Glucose Sensing

We developed a plasmonic cuvette that integrates plasmonic interferometry with enzyme-driven dye chemistry, enabling highly sensitive, label-free glucose detection in saliva. This system achieves a detection limit of ~0.1 μM and operates with sample volumes as low as picoliters, making it a viable candidate for non-invasive diabetes diagnostics.

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Nano Letters, 2012 – Nanoscale Plasmonic Interferometers for Multispectral, High-Throughput Biochemical Sensing

We developed a groove-slit-groove (GSG) plasmonic interferometer that enables multispectral, high-throughput biosensing, with a detection resolution of ~3 × 10⁻⁷ RIU and an ultra-low sensing volume of 20 fL. This sensor surpasses conventional SPR platforms by offering broadband spectral tunability, superior sensitivity, and scalable integration for lab-on-a-chip applications.

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This section explores the fundamental physics governing light transmission through isolated nanoapertures in metal films, emphasizing the transition between geometric and subwavelength optical regimes.

Journal of the Optical Society of America B, 2014 – Polarization Dependence of Light Transmission through Individual Nanoapertures in Metal Films

This study investigates the physics of light transmission through subwavelength nanoapertures in metal films, revealing universal trends that govern optical behavior across different aperture shapes and sizes. By combining experimental measurements with theoretical analyses, we establish fundamental scaling laws that describe the transition from geometric optics to the subwavelength regime. We demonstrate that individual nanoapertures act as high-extinction-ratio polarizers (>100:1) and identify key conditions for plasmonic mode excitation and polarization-selective transmission. These findings provide insights into nanophotonic device optimization, polarization-sensitive optical elements, and next-generation plasmonic circuits.

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