All Outputs (12)

Comparison of rigorous scattering models to accurately replicate the behaviour of scattered electromagnetic waves in optical surface metrology (2024)
Journal Article
Hooshmand, H., Pahl, T., Hansen, P.-E., Fu, L., Birk, A., Karamehmedović, M., Lehmann, P., Reichelt, S., Leach, R., & Piano, S. (2025). Comparison of rigorous scattering models to accurately replicate the behaviour of scattered electromagnetic waves in optical surface metrology. Journal of Computational Physics, 521, Article 113519. https://doi.org/10.1016/j.jcp.2024.113519

Rigorous scattering models are based on Maxwell's equations and can provide high-accuracy solutions to model electromagnetic wave scattering from objects. Being able to calculate the scattered field from any surface geometry and considering the effec... Read More about Comparison of rigorous scattering models to accurately replicate the behaviour of scattered electromagnetic waves in optical surface metrology.

Applying machine learning to optical metrology: a review (2024)
Journal Article
Xue, R., Hooshmand, H., Isa, M., Piano, S., & K Leach, R. (2024). Applying machine learning to optical metrology: a review. Measurement Science and Technology, 36(1), Article 012002. https://doi.org/10.1088/1361-6501/ad7878

This literature review investigates the integration of machine learning (ML) into optical metrology, unveiling enhancements in both efficiency and effectiveness of measurement processes. With a focus on phase demodulation, unwrapping, and phase-to-he... Read More about Applying machine learning to optical metrology: a review.

In-situ measurement methods for microscale surface impurities in powder bed fusion: a review (2024)
Journal Article
Koca, A., Hooshmand, H., Leach, R., & Liu, M. (2025). In-situ measurement methods for microscale surface impurities in powder bed fusion: a review. Measurement Science and Technology, 36(1), Article 012001. https://doi.org/10.1088/1361-6501/ad824c

Despite ongoing improvements and optimisation efforts, the powder bed fusion (PBF) process continues to face challenges related to repeatability, robustness, and stability. These challenges can lead to the formation of microscale surface impurities o... Read More about In-situ measurement methods for microscale surface impurities in powder bed fusion: a review.

Extracting focus variation data from coherence scanning interferometric measurements (2024)
Journal Article
Liu, J., Hooshmand, H., Piano, S., Leach, R., Coupland, J., Ren, M., …Su, R. (2024). Extracting focus variation data from coherence scanning interferometric measurements. Precision Engineering, 88, 699-706. https://doi.org/10.1016/j.precisioneng.2024.04.016

Coherence scanning interferometry (CSI), based on the principle of interference, can achieve sub-nanometer precision for height measurements. On the other hand, focus variation microscopy (FVM), combining the small depth of field of the objective, is... Read More about Extracting focus variation data from coherence scanning interferometric measurements.

Comparison of Fourier optics-based methods for modeling coherence scanning interferometry (2024)
Journal Article
Hooshmand, H., Pahl, T., de Groot, P. J., Lehmann, P., Pappas, A., Su, R., …Piano, S. (2024). Comparison of Fourier optics-based methods for modeling coherence scanning interferometry. Optical Engineering, 63(4), Article 044102. https://doi.org/10.1117/1.OE.63.4.044102

Coherence scanning interferometry (CSI) is a widely used optical method for surface topography measurement of industrial and biomedical surfaces. The operation of CSI can be modeled using approximate physics-based approaches with minimal computationa... Read More about Comparison of Fourier optics-based methods for modeling coherence scanning interferometry.

Dynamic surface displacement measurement using carrier optical vortex interferometer: A numerical study (2023)
Journal Article
Dong, J., Hooshmand, H., Liu, M., & Piano, S. (2023). Dynamic surface displacement measurement using carrier optical vortex interferometer: A numerical study. Optics and Lasers in Engineering, 171, Article 107824. https://doi.org/10.1016/j.optlaseng.2023.107824

The measurement of dynamic surface displacement is crucial in understanding mechanical and thermophysical dynamics at nanometre to micrometre-scale. Interferometers using optical vortices are gaining attention due to their ability to demodulate fring... Read More about Dynamic surface displacement measurement using carrier optical vortex interferometer: A numerical study.

Quantitative investigation of the validity conditions for the Beckmann-Kirchhoff scattering model (2022)
Journal Article
Hooshmand, H., Liu, M., Leach, R., & Piano, S. (2022). Quantitative investigation of the validity conditions for the Beckmann-Kirchhoff scattering model. Optical Engineering, 61(12), Article 124113. https://doi.org/10.1117/1.OE.61.12.124113

Approximate and rigorous methods are widely used to model light scattering from a surface. The boundary element method (BEM) is a rigorous model that accounts for polarization and multiple scattering effects. BEM is suitable to model the scattered li... Read More about Quantitative investigation of the validity conditions for the Beckmann-Kirchhoff scattering model.

Quantifying the validity conditions of the Beckmann-Kirchhoff scattering model
Presentation / Conference Contribution
Hooshmand, H., Liu, M., Leach, R., & Piano, S. (2022, August). Quantifying the validity conditions of the Beckmann-Kirchhoff scattering model. Presented at SPIE Optical Engineering + Applications 2022, San Diego, California, United States

Approximate and rigorous methods are widely used to model light scattering from a surface. The boundary element method (BEM) is a rigorous model that accounts for polarisation and multiple scattering effects. BEM is suitable to model the scattered li... Read More about Quantifying the validity conditions of the Beckmann-Kirchhoff scattering model.

Comparison of approximate methods for modelling coherence scanning interferometry
Presentation / Conference Contribution
Hooshmand, H., Pahl, T., de Groot, P. J., Lehmann, P., Pappas, A., Su, R., Leach, R., & Piano, S. Comparison of approximate methods for modelling coherence scanning interferometry. Presented at Modeling Aspects in Optical Metrology IX, Munich, Germany

Coherence scanning interferometry (CSI) is a widely used optical method for surface topography measurement of industrial and biomedical surfaces. The operation of CSI can be modelled using approximate physics-based approaches with minimal computation... Read More about Comparison of approximate methods for modelling coherence scanning interferometry.

Comparison of coherence scanning interferometry, focus variation and confocal microscopy for surface topography measurement
Presentation / Conference Contribution
Hooshmand, H., Liu, M., Pappas, A., Thompson, A., Leach, R., & Piano, S. (2023, June). Comparison of coherence scanning interferometry, focus variation and confocal microscopy for surface topography measurement. Presented at Euspen’s 23rd International Conference & Exhibition, Copenhagen, Denmark

The most common optical technologies for surface topography measurement are coherence scanning interferometry (CSI), focus variation microscopy (FV) and imaging confocal microscopy (CM). Due to the benefits and drawbacks of each, these instruments ar... Read More about Comparison of coherence scanning interferometry, focus variation and confocal microscopy for surface topography measurement.

Investigating the variation of particle distribution and surface texture of top surfaces based on build position in laser powder bed fusion
Presentation / Conference Contribution
Sithole, C., Hooshmand, H., Todhunter, L., Thompson, A., Hoekstra, S., Jalalian, A., Piano, S., & Gibson, I. Investigating the variation of particle distribution and surface texture of top surfaces based on build position in laser powder bed fusion. Presented at 7th CIRP Conference on Surface Integrity, Bremen, Germany

Quality analysis of additively manufactured (AM) surfaces is complex, yet critical for determining the functionality of parts and technology improvement. To accurately assess the quality of AM parts, it is necessary to consider the industrial applica... Read More about Investigating the variation of particle distribution and surface texture of top surfaces based on build position in laser powder bed fusion.

Evaluating approximate and rigorous scattering models in virtual coherence scanning interferometry for improved surface topography measurement
Presentation / Conference Contribution
Hooshmand, H., Isa, M. A., Nikolaev, N., Piano, S., & Leach, R. (2024, August). Evaluating approximate and rigorous scattering models in virtual coherence scanning interferometry for improved surface topography measurement. Presented at Optical Manufacturing and Testing 2024, San Diego, USA

In optical metrology, the growing demand for accurate measurement technologies is driven by the increasing applications of three-dimensional (3D) microscopy and imaging. The advancement of these technologies relies on the modelling of the measurement... Read More about Evaluating approximate and rigorous scattering models in virtual coherence scanning interferometry for improved surface topography measurement.