All Outputs (21)

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), 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'.

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.

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.

Analysis of noise in differential and ratiometric biosensing systems (2018)
Journal Article
Abayzeed, S., Smith, R. J., See, C. W., & Somekh, M. G. (2018). Analysis of noise in differential and ratiometric biosensing systems. Sensors and Actuators B: Chemical, 260, 1059-1067. https://doi.org/10.1016/j.snb.2018.01.004

This paper presents formulations to evaluate noise in differential and ratiometric measurements that are often performed in biosensing. These measurements are performed to improve signal to noise ratio of the sensing systems for sensitive detection o... Read More about Analysis of noise in differential and ratiometric biosensing systems.

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. (in press). Sensitive detection of voltage transients using differential intensity surface plasmon resonance system. Optics Express, 25(25), 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.

Sub-100 nm resolution microscopy based on proximity projection grating scheme (2015)
Journal Article
Hu, F., Somekh, M. G., Albutt, D. J., Webb, K., Moradi, E., & See, C. W. (2015). Sub-100 nm resolution microscopy based on proximity projection grating scheme. Scientific Reports, 5, https://doi.org/10.1038/srep08589

Structured illumination microscopy (SIM) has been widely used in life science imaging applications. The maximum resolution improvement of SIM, compared to conventional bright field system is a factor of 2. Here we present an approach to structured il... Read More about Sub-100 nm resolution microscopy based on proximity projection grating scheme.

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), 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.

Surface plasmon microscopic sensing with beam profile modulation (2012)
Journal Article
Zhang, B., Pechprasarn, S., & Somekh, M. G. (2012). Surface plasmon microscopic sensing with beam profile modulation. Optics Express, 20(27), https://doi.org/10.1364/OE.20.028039

Surface Plasmon microscopy enables measurement of local refractive index on a far finer scale than prism based systems. An interferometric or confocal system gives the so-called V(z) curve when the sample is scanned axially, which gives a measure of... Read More about Surface plasmon microscopic sensing with beam profile modulation.

Determination of crystallographic orientation of large grain metals with surface acoustic waves (2012)
Journal Article
Li, W., Sharples, S. D., Smith, R. J., Clark, M., & Somekh, M. G. (2012). Determination of crystallographic orientation of large grain metals with surface acoustic waves. Journal of the Acoustical Society of America, 132(2), 738-745. https://doi.org/10.1121/1.4731226

A previously described laser ultrasonic technique known as spatially resolved acoustic spectroscopy (SRAS) can be used to image surface microstructure, using the local surface acoustic wave (SAW) velocity as a contrast mechanism. It is shown here tha... Read More about Determination of crystallographic orientation of large grain metals with surface acoustic waves.

Confocal surface plasmon microscopy with pupil function engineering (2012)
Journal Article
Zhang, B., Pechprasarn, S., Zhang, J., & Somekh, M. G. (2012). Confocal surface plasmon microscopy with pupil function engineering. Optics Express, 20(7), https://doi.org/10.1364/OE.20.007388

Surface Plasmon microscopy can measure local changes of refractive index on the micron scale. Interferometric plasmon imaging delivers quantitative high spatial resolution sensitive to refractive index. In addition the so called V(z) method allows im... Read More about Confocal surface plasmon microscopy with pupil function engineering.

CHOTs optical transducers (2011)
Journal Article
Arca, A., Aylott, J., Marques, L., Clark, M., Somekh, M., Smith, R., …Chen, X. (2011). CHOTs optical transducers. Nondestructive Testing and Evaluation, 26(3-4), 353-366. https://doi.org/10.1080/10589759.2011.573555

Laser ultrasonics conventionally use direct absorption in the sample to generate ultrasound and monitor the sample to detect the ultrasound. However, in some circumstances there are significant advantages to using an optical transducer - a device to... Read More about CHOTs optical transducers.

The Design of a Real Time VLSI Optical Centroid Processor (2002)
Conference Proceeding
Pui, B. H., Hayes-Gill, B., Clark, M., Somekh, M., See, C., Morgan, S., & Ng, A. (2002). The Design of a Real Time VLSI Optical Centroid Processor. In IEEE Sensors 2002 : first IEEE International Conference on Sensors. https://doi.org/10.1109/ICSENS.2002.1036977

A real time VLSI optical centroid processor has been developed as part of a larger Shack-Hartmann wavefront sensor system for applications in adaptive optics. The implementation of the optical centroid detection system was demonstrated successfully u... Read More about The Design of a Real Time VLSI Optical Centroid Processor.