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Effect of skin color on optical properties and the implications for medical optical technologies: a review (2024)
Journal Article
Setchfield, K., Gorman, A., Simpson, A. H. R. W., Somekh, M. G., & Wright, A. J. (2024). Effect of skin color on optical properties and the implications for medical optical technologies: a review. Journal of Biomedical Optics, 29(01), Article 010901. https://doi.org/10.1117/1.jbo.29.1.010901

Significance: Skin color affects light penetration leading to differences in its absorption and scattering properties. COVID-19 highlighted the importance of understanding of the interaction of light with different skin types, e.g., pulse oximetry (P... Read More about Effect of skin color on optical properties and the implications for medical optical technologies: a review.

Relevance and utility of the in-vivo and ex-vivo optical properties of the skin reported in the literature: a review [Invited] (2023)
Journal Article
Setchfield, K., Gorman, A., Simpson, A. H. R. W., Somekh, M. G., & Wright, A. J. (2023). Relevance and utility of the in-vivo and ex-vivo optical properties of the skin reported in the literature: a review [Invited]. Biomedical Optics Express, 14(7), 3555-3583. https://doi.org/10.1364/boe.493588

Imaging non-invasively into the human body is currently limited by cost (MRI and CT scan), image resolution (ultrasound), exposure to ionising radiation (CT scan and X-ray), and the requirement for exogenous contrast agents (CT scan and PET scan). Op... Read More about Relevance and utility of the in-vivo and ex-vivo optical properties of the skin reported in the literature: a review [Invited].

Near-field manipulation of Tamm plasmon polaritons (2023)
Journal Article
Li, N., Zou, Q., Zhao, B., Min, C., Yuan, X., Somekh, M., & Feng, F. (2023). Near-field manipulation of Tamm plasmon polaritons. Optics Express, 31(5), 7321-7335. https://doi.org/10.1364/OE.481440

Tamm plasmon polaritons (TPPs) arise from electromagnetic resonant phenomena which appear at the interface between a metallic film and a distributed Bragg reflector. They differ from surface plasmon polaritons (SPPs), since TPPs possess both cavity m... Read More about Near-field manipulation of Tamm plasmon polaritons.

Design of a dynamic multi-topological charge graphene orbital angular momentum metalens (2023)
Journal Article
Cao, G., Lin, H., Jia, B., Yuan, X., Somekh, M., & Wei, S. (2023). Design of a dynamic multi-topological charge graphene orbital angular momentum metalens. Optics Express, 31(2), 2102-2111. https://doi.org/10.1364/OE.480946

Traditional OAM generation devices are bulky and can generally only create OAM with one specific topological charge. Although metasurface-based devices have overcome the volume limitations, no tunable metasurface-based OAM generators have been demons... Read More about Design of a dynamic multi-topological charge graphene orbital angular momentum metalens.

Non-iterative aberration retrieval based on the spot shape around focus (2022)
Journal Article
Smid, P., See, C. W., Somekh, M. G., & Wright, A. J. (2022). Non-iterative aberration retrieval based on the spot shape around focus. Optics and Lasers in Engineering, 157, Article 107108. https://doi.org/10.1016/j.optlaseng.2022.107108

A non-iterative, robust, aberration retrieval method to determine primary aberrations by utilizing the intensity distribution at and around focus is presented. The primary Zernike aberrations (coma, spherical aberration and astigmatism) are retrieved... Read More about Non-iterative aberration retrieval based on the spot shape around focus.

Analysis of Open Grating-Based Fabry–Pérot Resonance Structures With Potential Applications for Ultrasensitive Refractive Index Sensing (2021)
Journal Article
Sasivimolkul, S., Pechprasarn, S., & Somekh, M. G. (2021). Analysis of Open Grating-Based Fabry–Pérot Resonance Structures With Potential Applications for Ultrasensitive Refractive Index Sensing. IEEE Sensors Journal, 21(9), 10628-10636. https://doi.org/10.1109/jsen.2021.3063136

We report a theoretical framework to explain the characteristics of Fabry-Pérot (FP) resonances excited in a thin film-based grating consisting of a thin gold layer and a rectangular dielectric grating in the sub-wavelength and near-wavelength gratin... Read More about Analysis of Open Grating-Based Fabry–Pérot Resonance Structures With Potential Applications for Ultrasensitive Refractive Index Sensing.

Comments on 'Rapid Image Reconstruction of Structured Illumination Microscopy Directly in the Spatial Domain' (2021)
Journal Article
Somekh, M. (2021). Comments on 'Rapid Image Reconstruction of Structured Illumination Microscopy Directly in the Spatial Domain'. IEEE Photonics Journal, 13(2), Article 9600102. https://doi.org/10.1109/JPHOT.2021.3059562

This comment shows that the formulation used in the above paper has been presented in virtually the same form in a previous paper. The comment also emphasizes that spatial domain reconstruction for structured light microscopy is a useful supplement t... Read More about Comments on 'Rapid Image Reconstruction of Structured Illumination Microscopy Directly in the Spatial Domain'.

Single pixel camera methodologies for spatially resolved acoustic spectroscopy (2021)
Journal Article
Patel, R., Sharples, S. D., Clark, M., Somekh, M. G., & Li, W. (2021). Single pixel camera methodologies for spatially resolved acoustic spectroscopy. Applied Physics Letters, 118(5), Article 051102. https://doi.org/10.1063/5.0040123

Spatially resolved acoustic spectroscopy (SRAS) is a laser ultrasound technique used to determine the crystallographic orientation (i.e. microstructure) of materials through the generation and measurement of surface acoustic wave velocity on a sample... Read More about Single pixel camera methodologies for spatially resolved acoustic spectroscopy.

Virtual optics and sensing of the retrieved complex field in the back focal plane using a constrained defocus algorithm (2020)
Journal Article
Somekh, M. G., Shen, H., Chow, T. W. K., & Shen, M. (2020). Virtual optics and sensing of the retrieved complex field in the back focal plane using a constrained defocus algorithm. Optics Express, 28(22), 32777-32792. https://doi.org/10.1364/oe.404573

The reflected back focal plane from a microscope objective is known to provide excellent information of material properties and can be used to analyze the generation of surface plasmons and surface waves in a localized region. Most analysis has conce... Read More about Virtual optics and sensing of the retrieved complex field in the back focal plane using a constrained defocus algorithm.

On-chip plasmonic spin-Hall nanograting for simultaneously detecting phase and polarization singularities (2020)
Journal Article
Feng, F., Si, G., Min, C., Yuan, X., & Somekh, M. (2020). On-chip plasmonic spin-Hall nanograting for simultaneously detecting phase and polarization singularities. Light: Science and Applications, 9(1), Article 95. https://doi.org/10.1038/s41377-020-0330-z

Phase and polarization singularities are important degrees of freedom for electromagnetic field manipulation. Detecting these singularities is essential for modern optics, but it is still a challenge, especially in integrated optical systems. In this... Read More about On-chip plasmonic spin-Hall nanograting for simultaneously detecting phase and polarization singularities.

Defocus leakage radiation microscopy for single shot surface plasmon measurement (2020)
Journal Article
Chow, T. W. K., Lun, D. P. K., Pechprasarn, S., & Somekh, M. G. (2020). Defocus leakage radiation microscopy for single shot surface plasmon measurement. Measurement Science and Technology, 31(7), Article 075401. https://doi.org/10.1088/1361-6501/ab7def

Measurement of surface plasmon and surface wave propagation is important for the operation and characterization of sensors and microscope systems. One challenge is to perform these measurements both quickly and with good spatial resolution without an... Read More about Defocus leakage radiation microscopy for single shot surface plasmon measurement.

A General Description of the Performance of Surface Plasmon Sensors Using a Transmission Line Resonant Circuit Model (2019)
Journal Article
Shen, M., & Somekh, M. G. (2019). A General Description of the Performance of Surface Plasmon Sensors Using a Transmission Line Resonant Circuit Model. IEEE Sensors Journal, 19(23), 11281-11288. https://doi.org/10.1109/jsen.2019.2933320

We analyze the response of surface plasmon (SP) sensors using a transmission line model. We illustrate this analysis with particular reference to a layered structure in which plasmon hybridization occurs. By applying the appropriate resonant conditio... Read More about A General Description of the Performance of Surface Plasmon Sensors Using a Transmission Line Resonant Circuit Model.

Hybrid photonic-plasmonic platform for high-throughput single-molecule studies (2019)
Journal Article
Mossayebi, M., Parini, A., Wright, A. J., Somekh, M. G., Bellanca, G., & Larkins, E. C. (2019). Hybrid photonic-plasmonic platform for high-throughput single-molecule studies. Optical Materials Express, 9(6), 2511-2522. https://doi.org/10.1364/OME.9.002511

We present the design and numerical characterization of a hybrid photonic-plasmonic nanoresonator comprised of a 2D photonic crystal (PhC) cavity, a gold bowtie nanoantenna (BNA) and a silicon dioxide, SiO2, spacer. This device is designed to serve a... Read More about Hybrid photonic-plasmonic platform for high-throughput single-molecule studies.

Application of confocal surface wave microscope to self-calibrated attenuation coefficient measurement by Goos-Hänchen phase shift modulation (2018)
Journal Article
Pechprasarn, S., Chow, T. W. K., & Somekh, M. G. (2018). Application of confocal surface wave microscope to self-calibrated attenuation coefficient measurement by Goos-Hänchen phase shift modulation. Scientific Reports, 8, Article 8547. https://doi.org/10.1038/s41598-018-26424-2

In this paper, we present a direct method to measure surface wave attenuation arising from both ohmic and coupling losses using our recently developed phase spatial light modulator (phase-SLM) based confocal surface plasmon microscope. The measuremen... Read More about Application of confocal surface wave microscope to self-calibrated attenuation coefficient measurement by Goos-Hänchen phase shift modulation.

Sensitive detection of voltage transients using differential intensity surface plasmon resonance system (2017)
Journal Article
Abayzeed, S. A., Smith, R. J., Webb, K. F., Somekh, M. G., & See, C. W. (2017). Sensitive detection of voltage transients using differential intensity surface plasmon resonance system. Optics Express, 25(25), 31552-31567. https://doi.org/10.1364/OE.25.031552

This paper describes theoretical and experimental study of the fundamentals of using surface plasmon resonance (SPR) for label-free detection of voltage. Plasmonic voltage sensing relies on the capacitive properties of metal-electrolyte interface tha... Read More about Sensitive detection of voltage transients using differential intensity surface plasmon resonance system.

Investigating the use of a hybrid plasmonic-photonic nanoresonator for optical trapping using finite-difference time-domain method (2016)
Journal Article

We investigate the use of a hybrid nanoresonator comprising a photonic crystal (PhC) cavity coupled to a plasmonic bowtie nanoantenna (BNA) for the optical trapping of nanoparticles in water. Using finite-difference time-domain simulations, we show t... Read More about Investigating the use of a hybrid plasmonic-photonic nanoresonator for optical trapping using finite-difference time-domain method.

Live imaging of cellular internalization of single colloidal particle by combined label-free and fluorescence total internal reflection microscopy (2015)
Journal Article

In this work we utilize the combination of label-free total internal reflection microscopy and total internal reflectance fluorescence (TIRM/TIRF) microscopy to achieve a simultaneous, live imaging of single, label-free colloidal particle endocytosis... Read More about Live imaging of cellular internalization of single colloidal particle by combined label-free and fluorescence total internal reflection microscopy.

Monte Carlo photon simulation of an anti-confocal system to monitor middle ear inflammation (2015)
Presentation / Conference Contribution
Jung, D. S., Birchall, J. P., Crowe, J. A., See, C. W., & Somekh, M. G. (2015, April). Monte Carlo photon simulation of an anti-confocal system to monitor middle ear inflammation. Presented at OMP 2015 Optical Molecular Probes, Imaging and Drug Delivery, Vancouver, Canada

Monte Carlo simulations of an anti-confocal system to monitor middle ear inflammation showed that using a stop to reject the scattering plane, the eardrum, rather than a pinhole to select the imaging plane, improved the signal-to-background ratio.

Ultrastable embedded surface plasmon confocal interferometry (2014)
Journal Article
Pechprasarn, S., Zhang, B., Albutt, D., Zhang, J., & Somekh, M. (2014). Ultrastable embedded surface plasmon confocal interferometry. Light: Science and Applications, 3(7), Article e187. https://doi.org/10.1038/lsa.2014.68

As disease diagnosis becomes more sophisticated, there is a requirement to measure small numbers of molecules attached to, for instance, an antibody. This requires a sensor capable not only of high sensitivity but also the ability to make measurement... Read More about Ultrastable embedded surface plasmon confocal interferometry.