Author:Forbes, A; Masina, Bathusile NDate:Nov 2010In this article the authors outline how an all-optical system may be designed for the heating, and then subsequent temperature measurement, of any sample, thus allowing a non-contact approach to thermal studies of materialsRead more
Author:Ismail, Y; Barnes, G; Mhlanga, T; Belyi, V; Forbes, ADate:Mar 2010In this paper the authors outline an optical design for producing high-order Bessel-like beams with a z-dependent cone angle through the use of conventional optical elements, without the need for deliberate aberrations to be included.Read more
Author:Pityana, Sisa LDate:Mar 2010Laser surface alloying of A1200 aluminium alloy was carried out using a 4.4 kW Nd:YAG laser. Powder mixtures of SiC and TiC hard particles were injected into the laser generated melt pool on the aluminium substrate using a commercial powder ...Read more
Author:Dudley, Angela L; Nock, M; Konrad, T; Roux, FS; Forbes, ADate:Oct 2010An amplitude damping channel for Laguerre-Gaussian (LG) modes is presented. Experimentally the action of the channel on LG modes is in good agreement with that predicted theoretically.Read more
Author:Flamm, D; Naidoo, Darryl; Schulze, C; Forbes, A; Duparré, MDate:Jul 2012A procedure for the real-time analysis of laser modes using a phase-only spatial light modulator is outlined. The procedure involves encoding into digital holograms by complex amplitude modulation a set of orthonormal basis functions into ...Read more
Author:Mafusire, C; Forbes, A; Michaelis, MM; Snedden, Glen CDate:Aug 2010Gas lenses work on the basis that aerodynamic media can be used to generate a graded refractive index distribution which can be used to focus a laser beam. Examples of these are the spinning pipe gas lens (SPGL) and the flame lens (FL). The ...Read more
Author:Ashok, AC; Marchington, RF; Mthunzi-Kufa, Patience; Krauss, TF; Dholakia, KDate:Mar 2010The authors describe the realization of integrated optical chromatography, in conjunction with on-chip fluorescence excitation, in a monolithically fabricated poly-dimethylsiloxane (PDMS) microfluidic chip. The unique endlessly-single-mode ...Read more
Author:Willers, Cornelius JDate:Sep 2009From its humble beginnings in an optical workshop in the Mowbray office for Triangulation in the 1930s and the subsequent formation of the Division for Optics and Spectroscopy at the National Physical Research Laboratory within the CSIR during ...Read more
Author:Ismail, Y; Mclaren, MG; Forbes, ADate:Jul 2009This presentation provides information on optical trapping and tweezing using a spatial light modulator.Read more
Author:Romero, J; Giovannini, D; McLaren, MG; Galvez, EJ; Forbes, A; Padgett, MJDate:Aug 2012We report orbital angular momentum (OAM) and angle correlations between signal and idler photons observed when the nonlinear crystal used in spontaneous parametric down-conversion is illuminated by a non-fundamental Gaussian pump beam. We ...Read more
Author:Moraal, H; Britton, D; Derry, T; Forbes, A; Grayson, D; Mullins, S; Scholtz, F; Sefako, RDate:2009The chapter is about physics and astronomy. The chapter gives a background about the origins of physics in South Africa. After the CSIR was founded in 1945, physics emerged as a nationwide and unified discipline. The authors show how physics ...Read more
Author:Bollig, C; Jacobs, Cobus; Esser, MJD; Bernhard, EH; Von Bergmann, HMDate:Jun 2010An end-pumped Nd:YLF laser was demonstrated, which delivered 60.3 W continuous-wave and more than 52 W Q-switched average power for all repetition rates from 5 to 30 kHz. To achieve this, an analytical solution to estimate and optimize the ...Read more
Author:Dudley, Angela L; Litvin, IA; Forbes, ADate:Mar 2012In this work we derive expressions for the orbital angular momentum (OAM) density of light, for both symmetric and nonsymmetric optical fields, that allow a direct comparison between theory and experiment. We present a simple method for ...Read more
Author:Lavery, MPJ; Dudley, Angela L; Forbes, A; Courtial, J; Padgett, MJDate:Sep 2011The authors have developed an interferometer requiring only minimal angular alignment for the routing of beams carrying orbital angular momentum. The Mach–Zehnder interferometer contains a Dove prism in each arm where each has a mirror plane ...Read more
Author:Belyi, VN; Kazak, NS; Khilo, NA; Forbes, A; Ropot, PIDate:Nov 2011In this paper the authors consider the angular spectrum of an apertured Bessel beam when the aperture is circular and shifted laterally with respect to the optical axis. Since the perturbation of the resulting angular spectrum is due to a ...Read more
Author:Litvin, IADate:May 2013In this paper we present a general approach to determine the stability of a laser cavity which can include non-conventional phase transformation elements. We consider two pertinent examples of the detailed investigation of the stability of a ...Read more
Author:Godin, T; Ngcobo, Sandile; Cagniot, E; Fromager, M; Forbes, A; Aït-Ameur, KDate:Aug 2011Many applications of lasers seek nowadays for focal spots whose corresponding volume is getting smaller and smaller in order to ensure high spatial resolution. This problem, studied by many research groups around the world, is the core of ...Read more
Author:Dudley, Angela L; Vasilyeu, R; Forbes, A; Khilo, N; Ropot, P; Belyi, V; Kazak, NDate:Aug 2009This paper presents a mechanism for the generation of the superposition of higher-order Bessel beams, which implements a ring slit aperture and spatial light modulator (SLM). The experimental technique is also adapted to generate nondiffracting ...Read more
Author:Dudley, Angela L; Vasilyeu, R; Forbes, A; Khilo, N; Ropot, PDate:Jul 2009This poster presents a mechanism for the generation of the superposition of higher-order Bessel beams, which implements a ring slit aperture and spatial light modulator (SLM). The experimental technique is also adapted to generate nondiffracting ...Read more
Author:Godin, T; Forbes, A; Naidoo, Darryl; Fromager, M; Cagniot, E; Aït-Ameur, KDate:Jun 2011The concept of transverse correlation vanishing, between the fraction of power contained in the centre and wings of a probe beam, recently introduced [Opt. Commun. 282 (2009) 3854–3858] is important to be considered when measuring the effective ...Read more