Dr. Darryl Naidoo Profile

Dr. Darryl Naidoo

Research Associate at CSIR National Laser Ctr

SPIE Involvement:

Author | Leadership Workshop Facilitator

Publications (32)

Proceedings Article | 28 September 2023 Poster + Paper

Effect of astigmatism on the beam quality factor of Hermite-Gauss laser beams

Chemist Mabena, Nokwazi Mphuthi, Lebohang Bell, Darryl Naidoo

Proceedings Volume 12664, 126640L (2023) https://doi.org/10.1117/12.2677349

KEYWORDS: Monochromatic aberrations, Complex amplitude, Atmospheric propagation, Optical aberrations, Laser development, Laser beam propagation, Free space, Wave equations, Turbulence, Structured light

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Proceedings Article | 26 September 2023 Poster + Paper

Analytical analysis of the quality factor of quartically aberrated Laguerre-Gauss beams

Chemist Mabena, Teboho Bell, Nokwazi Mphuthi, Darryl Naidoo

Proceedings Volume 12667, 126670G (2023) https://doi.org/10.1117/12.2677337

KEYWORDS: Monochromatic aberrations, Analytical research, Structured light, Optical components, Beam analyzers, Digital signal processing, Complex amplitude, Chemical elements, Wave equations, Thermal effects

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Proceedings Article | 15 March 2023 Paper

Active control of focus position of laser beams using thermally induced lensing

Lebohang Bell, Chemist Mabena, Darryl Naidoo

Proceedings Volume 12407, 124070F (2023) https://doi.org/10.1117/12.2650353

KEYWORDS: Solid state lasers, Thermal lensing, Thermal optics, Beam diameter, Temperature distribution, Manufacturing, Refractive index, High power lasers

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Proceedings Article | 8 March 2023 Presentation + Paper

Modelling the effect of astigmatism on the beam quality factor of Laguerre-Gaussian optical beams

Chemist Mabena, Teboho Bell, Darryl Naidoo

Proceedings Volume 12399, 123990H (2023) https://doi.org/10.1117/12.2650192

KEYWORDS: Structured light, High power lasers, Thermal effects, Numerical simulations, Integral transforms, Finite element methods

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Proceedings Article | 1 August 2021 Presentation + Paper

Amplification of a propagation invariant vector flat-top beam

Justin Harrison, Andrew Forbes, Darryl Naidoo

Proceedings Volume 11818, 118180C (2021) https://doi.org/10.1117/12.2595120

KEYWORDS: Crystals, Laser crystals, Beam propagation method, Gaussian beams, Absorption, Spatial light modulators, Polarization, Nd:YAG lasers, Beam shaping, Spiral phase plates

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Proceedings Article | 1 August 2021 Presentation + Paper

Determination of amplification characteristics in end-pumped solid-state amplifiers

Justin Harrison, Darryl Naidoo, Andrew Forbes

Proceedings Volume 11818, 118180D (2021) https://doi.org/10.1117/12.2595121

KEYWORDS: Crystals, Laser crystals, Absorption, 3D modeling, Beam propagation method, Gaussian beams, Optical amplifiers, Nd:YAG lasers, Diodes, Beam shaping

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Master Oscillator Power Amplifier (MOPA) systems have garnered considerable interest to power scale low power seed beams (from the Master Oscillator) to higher powers. These systems are favourable to obtain the desired laser beam performance when additional optical elements such as Bragg gratings are required. These elements do not have to endure high optical intensities inside high-power oscillators and do not affect the beam quality or power efficiency. Power amplifiers consist of two primary architectures that include end-pumping and side-pumping. The latter offers greater amplification at the expense of increased thermally-induced beam distortions such as thermal lensing, while the former offers more controllable and efficient power scaling with a limit on the amplification potential. To date, the theoretical models describing the characteristics of end-pumped systems have been limited to two-dimensional crystal architectures with an approximation of the thermal lens as a two-dimensional element. In general, the optical pumping beam is over-simplified and does not reflect realworld spatial evolution over the entirety of the crystal rod length. These approximations hold for thin crystals operating under small-signal amplification, however, they are inaccurate for high signal amplification in long crystal rod geometries. In this work, we explore three-dimensional crystal rods in end-pumped configuration, using an in Infinitesimally sliced model, to study the amplification potential and thermal lens in end-pumped power amplifiers in greater detail while using beam shaping theory to model the pump beam transformation accurately over the length of the crystal. We verify our theoretical approach experimentally using a single amplifier stage in double-pass configuration for power scaling of Gaussian beams. We demonstrate over 95% correlation between our model and the corresponding experiment and show that this correlation extends over the small and high signal amplification regions. The improved model, experimental techniques and results outlined here will provide a valuable tool for advances towards optimizing high brightness amplifiers.

Proceedings Article | 13 March 2020 Presentation + Paper

High purity twisted light from a metasurface solid state resonator

Hend Sroor, Yao-Wei Huang, Bereneice Sephton, Darryl Naidoo, Adam Vallés, Vincent Ginis, Qiwen Zhan, Cheng-Wei Qiu, Antonio Ambrosio, Federico Capasso, Andrew Forbes

Proceedings Volume 11259, 112590H (2020) https://doi.org/10.1117/12.2546189

KEYWORDS: Polarization, Resonators, Mirrors, Laser processing, Solid state physics, Laser applications, Wave plates, Ferroelectric materials, Laser resonators, Imaging spectroscopy

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Proceedings Article | 13 March 2020 Presentation + Paper

Generation of arbitrary higher order Poincaré beams from a visible metasurface laser

Hend Sroor, Yao-Wei Huang, Bereneice Sephton, Darryl Naidoo, Adam Valles, Vincent Ginis, Qiwen Zhan, Cheng-Wei Qiu, Antonio Ambrosio, Federico Capasso, Andrew Forbes

Proceedings Volume 11266, 112660L (2020) https://doi.org/10.1117/12.2546267

KEYWORDS: Polarization, Superposition, Laser processing, Laser resonators, Laser applications, Poincaré sphere, Resonators, Beam shaping, Computer engineering, Optical components

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Proceedings Article | 9 September 2019 Paper

Amplification of higher-order Poincaré sphere beams

Darryl Naidoo, Hend Sroor, Igor Litvin, Andrew Forbes

Proceedings Volume 11107, 111070V (2019) https://doi.org/10.1117/12.2542294

KEYWORDS: Amplifiers, Polarization, Crystals, Nd:YAG lasers, Neodymium lasers, YAG lasers, Optical amplifiers, Spatial light modulators, Poincaré sphere, Birefringence

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Proceedings Article | 4 March 2019 Presentation + Paper

Layer-wise powder deposition defect detection in additive manufacturing

Adriaan Hendriks, R. Ramokolo, Chris Ngobeni, M. Moroko, Darryl Naidoo

Proceedings Volume 10909, 109090O (2019) https://doi.org/10.1117/12.2509571

KEYWORDS: Light sources, Defect detection, Image processing, Software development, Cameras, Scattering, Additive manufacturing, Metals, Surface roughness, Light scattering

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Proceedings Article | 22 February 2018 Presentation + Paper

Generation of fractal structured eigenmodes from lasers

Hend Sroor, Darryl Naidoo, Johannes Courtial, Andrew Forbes

Proceedings Volume 10549, 105490B (2018) https://doi.org/10.1117/12.2291019

KEYWORDS: Fractal analysis, Resonators, Mirrors, Diffraction, Laser resonators, Confocal microscopy, CCD cameras, Physics, Laser optics, Beam shaping

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Proceedings Article | 16 February 2018 Presentation + Paper

A novel laser resonator for fractal modes

Hend Sroor, Darryl Naidoo, Johannes Courtial, Andrew Forbes

Proceedings Volume 10518, 105181N (2018) https://doi.org/10.1117/12.2290958

KEYWORDS: Fractal analysis, Laser resonators, Resonators, Mirrors, Laser beam propagation, CCD cameras, Physics, Computer graphics, Image compression, Diffraction

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Proceedings Article | 16 February 2018 Presentation + Paper

Generation and amplification of vector vortex beams

Hend Sroor, Nyameko Lisa, Darryl Naidoo, Igor Litvin, Andrew Forbes

Proceedings Volume 10518, 105181T (2018) https://doi.org/10.1117/12.2291040

KEYWORDS: Crystals, Polarization, Laser crystals, Amplifiers, Neodymium lasers, Wave plates, Optical spheres, Tomography, Optical amplifiers, Beam splitters

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Proceedings Article | 15 February 2018 Presentation + Paper

Cylindrical vector beams through amplifiers

Hend Sroor, Nyameko Lisa, Darryl Naidoo, Igor Litvin, Andrew Forbes

Proceedings Volume 10511, 105111M (2018) https://doi.org/10.1117/12.2290902

KEYWORDS: Polarization, Crystals, Optical amplifiers, Neodymium lasers, Amplifiers, Laser crystals, High power lasers, Spatial light modulators, Modes of laser operation, Laser resonators

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Proceedings Article | 21 April 2017 Presentation

Unveiling the radial modes in vortex beams (Conference Presentation)

Prince Mredlana, Darryl Naidoo, Cosmas Mafusire, Angela Dudley, Tjaart Krüger, Andrew Forbes

Proceedings Volume 10090, 100901P (2017) https://doi.org/10.1117/12.2252000

KEYWORDS: Spiral phase plates, Coherence (optics), Wavefronts, Interferometers, Scientific research, Laser resonators, Current controlled current source, Optical components, Beam controllers, Microresonators

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Proceedings Article | 3 February 2017 Paper

Characterising laser beams with liquid crystal displays

Angela Dudley, Darryl Naidoo, Andrew Forbes

Proceedings Volume 10036, 100360W (2017) https://doi.org/10.1117/12.2244258

KEYWORDS: LCDs, Wavefronts, Sensors, CCD image sensors, Charge-coupled devices, Spatial light modulators, Spiral phase plates, Holograms, Multiplexing, Optical communications

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Proceedings Article | 3 February 2017 Paper

Improving the laser brightness of a commercial laser system

Darryl Naidoo, Igor Litvin, Andrew Forbes

Proceedings Volume 10036, 100360V (2017) https://doi.org/10.1117/12.2244293

KEYWORDS: Laser resonators, Mirrors, Gaussian beams, Laser systems engineering, Optical components, Diffractive optical elements, Beam propagation method, Output couplers, Resonators, Collimation

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Proceedings Article | 22 April 2016 Paper

Thermal lensing measurement from the coefficient of defocus aberration using Shack-Hartmann wavefront sensor

Teboho Bell, Darryl Naidoo, Sandile Ngcobo, Andrew Forbes

Proceedings Volume 9727, 97271L (2016) https://doi.org/10.1117/12.2205141

KEYWORDS: Wavefront sensors, Solid state lasers, Nd:YAG lasers, Laser resonators, Resonators, Collimation, Gaussian beams, Laser beam diagnostics, Mirrors, Crystals, Calibration, Laser crystals, Wavefronts

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Proceedings Article | 25 August 2015 Paper

Selective excitation and detection of higher-order doughnut laser modes as an incoherent superposition of two petals modes in a digital laser resonator

Sandile Ngcobo, Teboho Bell, Igor Litvin, Darryl Naidoo, Kamel Ait-Ameur, Andrew Forbes

Proceedings Volume 9581, 95810B (2015) https://doi.org/10.1117/12.2187892

KEYWORDS: Superposition, Laser resonators, Digital holography, Mirrors, Modes of laser operation, Spatial light modulators, Resonators, Holograms, Beam propagation method, Opacity

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SPIE Journal Paper | 6 July 2015

Radially polarized cylindrical vector beams from a monolithic microchip laser

Darryl Naidoo, Michael Fromager, Kamel Äit-Ameur, Andrew Forbes

OE, Vol. 54, Issue 11, 111304, (July 2015) https://doi.org/10.1117/12.10.1117/1.OE.54.11.111304

KEYWORDS: Laser crystals, Crystals, Polarization, Beam shaping, Linear polarizers, Superposition, Polarizers, Gaussian beams, Diffractive optical elements, Optical engineering

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Proceedings Article | 3 March 2015 Paper

Generation of shape-invariant flat-top laser beams

Kamel Ait-Ameur, Darryl Naidoo, Sandile Ngcobo, Michael Fromager, Igor Litvin, Abdelkrim Hasnaoui, Ali Harfouche, Andrew Forbes

Proceedings Volume 9343, 93430P (2015) https://doi.org/10.1117/12.2075576

KEYWORDS: Mirrors, Gaussian beams, Near field optics, Laser resonators, Beam shaping, Interferometry, Near field, Spatial light modulators, Reflectivity, Laser beam propagation

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Proceedings Article | 2 October 2014 Paper

Digital holograms for laser mode multiplexing

Thandeka Mhlanga, Abderrahmen Trichili, Angela Dudley, Darryl Naidoo, Mourad Zghal, Andrew Forbes

Proceedings Volume 9194, 91941B (2014) https://doi.org/10.1117/12.2062999

KEYWORDS: Holograms, Digital holography, Multiplexing, Wavefronts, Spatial light modulators, Modes of laser operation, Optical communications, Data transmission, Single mode fibers, Signal detection

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Proceedings Article | 2 October 2014 Paper

Laguerre Gaussian beam multiplexing through turbulence

Abderrahmen Trichili, Thandeka Mhlanga, Darryl Naidoo, Angela Dudley, Mourad Zghal, Andrew Forbes

Proceedings Volume 9194, 91941A (2014) https://doi.org/10.1117/12.2062217

KEYWORDS: Multiplexing, Turbulence, Digital holography, Atmospheric turbulence, Holograms, Electroluminescent displays, Gaussian beams, Optical communications, Superposition, CCD cameras

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Proceedings Article | 17 July 2014 Open Access

Expansion of student activities in Africa: from south to north

Rim Cherif, Amine Ben Salem, Amor Gueddana, Mourad Zghal, Darryl Naidoo, Andrew Forbes, Alexander Heidt, Erich Rohwer

Proceedings Volume 9289, 928914 (2014) https://doi.org/10.1117/12.2070775

KEYWORDS: Photonics, Communication engineering, Physics, Active optics, Roads, Ions, Optical communications, Silica, Laser marking, Electroluminescence

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Proceedings Article | 4 March 2014 Paper

Intra-cavity metamorphosis of a Gaussian beam to flat-top distribution

Darryl Naidoo, Igor Litvin, Alexander Laskin, Andrew Forbes

Proceedings Volume 8960, 89601H (2014) https://doi.org/10.1117/12.2039106

KEYWORDS: Gaussian beams, Mirrors, Spatial light modulators, Laser resonators, Optical components, Beam propagation method, Chemical elements, Beam shaping, Optical design, Solid state lasers

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Proceedings Article | 25 February 2014 Paper

Spatial superpositions of Gaussian beams

Darryl Naidoo, Thomas Godin, Michael Fromager, Kamel Aϊt-Ameur, Andrew Forbes

Proceedings Volume 8999, 89991J (2014) https://doi.org/10.1117/12.2039033

KEYWORDS: Gaussian beams, Spatial light modulators, Superposition, Phase shifts, Modulation, Beam shaping, Diffractive optical elements, Beam propagation method, Interferometry, Mach-Zehnder interferometers

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Proceedings Article | 5 March 2013 Paper

Mode analysis using the correlation filter method

Daniel Flamm, Christian Schulze, Darryl Naidoo, Andrew Forbes, Michael Duparré

Proceedings Volume 8637, 863717 (2013) https://doi.org/10.1117/12.2004557

KEYWORDS: Image filtering, Optical filters, Computer generated holography, Diffraction, Phase shift keying, Single mode fibers, Holograms, Holography, Near field optics, Step index fibers

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Proceedings Article | 22 February 2013 Paper

Unraveling light with digital holograms

A. Forbes, C. Schulze, S. Ngcobo, D. Flamm, D. Naidoo, A. Dudley, M. Duparre

Proceedings Volume 8600, 86000U (2013) https://doi.org/10.1117/12.2010842

KEYWORDS: Digital holography, Holograms, Wavefronts, Superposition, Computer generated holography, Optical fibers, Spatial light modulators, Wavefront sensors, Semiconductor lasers, Structured light

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Proceedings Article | 15 October 2012 Paper

The generation of flat-top beams by complex amplitude modulation with a phase-only spatial light modulator

Adriaan Hendriks, Darryl Naidoo, Filippus Roux, Carlos López-Mariscal, Andrew Forbes

Proceedings Volume 8490, 849006 (2012) https://doi.org/10.1117/12.932224

KEYWORDS: Phase shift keying, Spatial light modulators, Gaussian beams, Amplitude modulation, Computer generated holography, Transmittance, Phase modulation, Diffraction, Reflectivity, Computer programming

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Proceedings Article | 7 September 2011 Paper

Intracavity vortex beam generation

Darryl Naidoo, Kamel Aït-Ameur, Andrew Forbes

Proceedings Volume 8130, 813009 (2011) https://doi.org/10.1117/12.902330

KEYWORDS: Resonators, Spatial light modulators, Superposition, Beam shaping, Holograms, Spiral phase plates, Digital holography, Gaussian beams, Laser resonators, Prisms

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Proceedings Article | 19 February 2011 Paper

Intra-cavity decomposition of a dual-directional laser beam

Darryl Naidoo, Andrew Forbes, Kamel Aït-Ameur, Michael Fromager

Proceedings Volume 7913, 79131F (2011) https://doi.org/10.1117/12.876855

KEYWORDS: Mirrors, Resonators, Laser beam propagation, Gaussian beams, Diffraction, Beam propagation method, Beam shaping, Output couplers, Radio propagation, Diffractive optical elements

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Proceedings Article | 19 February 2011 Paper

Constructing petal modes from the coherent superposition of Laguerre-Gaussian modes

Darryl Naidoo, Andrew Forbes, Kamel Ait-Ameur, Marc Brunel

Proceedings Volume 7913, 791304 (2011) https://doi.org/10.1117/12.876854

KEYWORDS: Superposition, Resonators, Laser resonators, Visualization, Prisms, Spatial light modulators, Computer simulations, Solid state lasers, Mirrors, Mode locking

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Showing 5 of 32 publications

Conference Committee Involvement (3)

Photonic Instrumentation Engineering VI

5 February 2019 | San Francisco, California, United States

Photonic Instrumentation Engineering V

30 January 2018 | San Francisco, California, United States

Photonic Instrumentation Engineering IV

31 January 2017 | San Francisco, California, United States

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