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E.j.d. Vredenbregt - One of the best experts on this subject based on the ideXlab platform.
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measurements of the energy distribution of a high brightness rubidium ion Beam
Ultramicroscopy, 2018Co-Authors: Ten G Haaf, S.h.w. Wouters, D. F. J. Nijhof, P. H. A. Mutsaers, E.j.d. VredenbregtAbstract:Abstract The energy distribution of a high brightness rubidium ion Beam, which is intended to be used as the source for a focused ion Beam instrument, is measured with a retarding field analyzer. The ions are created from a Laser-cooled and compressed atomic Beam by two-step photoionization in which the ionization Laser power is enhanced in a build-up cavity. Particle tracing simulations are performed to ensure the analyzer is able to resolve the distribution. The lowest achieved full width 50% energy spread is (0.205 ± 0.006) eV, which is measured at a Beam current of 9 pA. The energy spread originates from the variation in the ionization position of the ions which are created inside an extraction electric field. This extraction field is essential to limit disorder-induced heating which can decrease the ion Beam brightness. The ionization position distribution is limited by a tightly focused Excitation Laser Beam. Energy distributions are measured for various ionization and Excitation Laser intensities and compared with calculations based on numerical solutions of the optical Bloch equations including ionization. A good agreement is found between measurements and calculations.
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cavity enhanced photoionization of an ultracold rubidium Beam for application in focused ion Beams
Physical Review A, 2017Co-Authors: Ten G Haaf, S.h.w. Wouters, P. H. A. Mutsaers, E.j.d. VredenbregtAbstract:A two-step photoionization strategy of an ultracold rubidium Beam for application in a focused ion Beam instrument is analyzed and implemented. In this strategy the atomic Beam is partly selected with an aperture after which the transmitted atoms are ionized in the overlap of a tightly cylindrically focused Excitation Laser Beam and an ionization Laser Beam whose power is enhanced in a build-up cavity. The advantage of this strategy, as compared to without the use of a build-up cavity, is that higher ionization degrees can be reached at higher currents. Optical Bloch equations including the photoionization process are used to calculate what ionization degree and ionization position distribution can be reached. Furthermore, the ionization strategy is tested on an ultracold Beam of $^{85}\mathrm{Rb}$ atoms. The Beam current is measured as a function of the Excitation and ionization Laser Beam intensity and the selection aperture size. Although details are different, the global trends of the measurements agree well with the calculation. With a selection aperture diameter of $52\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{m}$, a current of $\left(170\ifmmode\pm\else\textpm\fi{}4\right)$ pA is measured, which according to calculations is 63% of the current equivalent of the transmitted atomic flux. Taking into account the ionization degree the ion Beam peak reduced brightness is estimated at $1\ifmmode\times\else\texttimes\fi{}{10}^{7}$ A/(${\mathrm{m}}^{2}\phantom{\rule{0.16em}{0ex}}\mathrm{sr}\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$).
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Measurements of the energy distribution of an ultracold rubidium ion Beam
arXiv: Atomic Physics, 2017Co-Authors: G. Ten Haaf, S.h.w. Wouters, D. F. J. Nijhof, P. H. A. Mutsaers, E.j.d. VredenbregtAbstract:The energy distribution of an ultracold rubidium ion Beam, which is intended to be used as the source for a focused ion Beam instrument, is measured with a retarding field analyzer. The ions are created from a Laser-cooled and compressed atomic Beam by two-step photoionization in which the ionization Laser power is enhanced in a build-up cavity. Particle tracing simulations are performed to ensure the analyzer is able to resolve the distribution. The lowest achieved full width 50% energy spread is $\left(0.205\pm0.006\right)$ eV. The energy spread originates from the variation in the ionization position of the ions which are created inside an extraction electric field. This extraction field is essential to limit disorder-induced heating which can decrease the ion Beam brightness. The ionization position distribution is limited by a tightly focused Excitation Laser Beam. Energy distributions are measured for various ionization and Excitation Laser intensities and compared with calculations based on numerical solutions of the optical Bloch equations including ionization. A good agreement is found between measurements and calculations.
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Two step photo-ionization of a Laser cooled and compressed thermal atomic Beam for use in a focused ion Beam
2016Co-Authors: G. Ten Haaf, S.h.w. Wouters, P. H. A. Mutsaers, Tim C.h. De Raadt, O.j. Luiten, E.j.d. VredenbregtAbstract:Photo-ionization is applied to a Laser cooled and compressed atomic rubidium Beam in order to generate a high brightness ion Beam. When focused, this ion Beam can be used to image and edit integrated circuits at the nano-scale which is important for the ongoing reduction of feature sizes in the semiconductor industry. Experiments have shown that an atomic Beam brightness in excess of 106 A/(m2 sr eV) can be achieved with a flux equivalent to 500 pA in a compact magneto-optical compressor which should be sufficient to generate ion spots of 1 nm. Currently, photo-ionization experiments are being carried out that aim at ionizing the majority of the atoms within a small longitudinal range in order to minimize the longitudinal energy spread. The two step ionization setup uses a tightly focused Excitation Laser Beam and a powerful blue Laser coupled to a build-up-cavity.
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Optimization of the current extracted from an ultracold ion source
New Journal of Physics, 2012Co-Authors: N. Debernardi, P. H. A. Mutsaers, O.j. Luiten, R.w.l. Van Vliembergen, W.j. Engelen, K.h.m. Hermans, M.p. Reijnders, S.b. Van Der Geer, E.j.d. VredenbregtAbstract:Photoionization of trapped atoms is a recent technique for creating ion Beams with low transverse temperature. The temporal behavior of the current that can be extracted from such an ultracold ion source is measured when operating in the pulsed mode. A number of experimental parameters are varied to find the conditions under which the time-averaged current is maximized. A dynamic model of the source is developed that agrees quite well with the experimental observations. The radiation pressure exerted by the Excitation Laser Beam is found to substantially increase the extracted current. For a source volume with a typical root-mean-square radius of 20µm, a maximum peak current of 88pA is observed, limited by the available ionization Laser power of 46mW. The optimum time-averaged current is 13pA at a 36% duty cycle. Particle-tracking simulations show that stochastic heating strongly reduces the brightness of the ion Beam at higher current for the experimental conditions.
Tomasz Kawalec - One of the best experts on this subject based on the ideXlab platform.
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Tailoring optical discs for surface plasmon polaritons generation.
Nanotechnology, 2019Co-Authors: Aleksandra Sierant, Roman Panaś, Jacek Fiutowski, Horst-günter Rubahn, Tomasz KawalecAbstract:The article reports on an optimization of gold submicron structures based on modified recordable blank digital versatile discs for surface plasmon polaritions Excitation, mainly in near-infrared region. We have examined internal layers of commercially available DVD+R, DVD-R, DVD+RW and DVD-RW optical discs and we have elaborated a simple, inexpensive approach providing sharp resonances with efficiency reaching 95% for collimated Excitation Laser Beams. We have experimentally and numerically confirmed the SPPs intensity being up to 220 times the intensity of the Excitation Laser Beam. We have also directly measured thermal energy loss accompanying SPPs Excitation.
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Surface Plasmon Polaritons Probed with Cold Atoms
Plasmonics, 2017Co-Authors: Tomasz Kawalec, Aleksandra Sierant, Roman Panaś, Jacek Fiutowski, Dobrosława Bartoszek-bober, L. Jozefowski, Horst-günter RubahnAbstract:We report on an optical mirror for cold rubidium atoms based on a repulsive dipole potential created by means of a modified recordable digital versatile disc. Using the mirror, we have determined the absolute value of the surface plasmon polariton (SPP) intensity, reaching 90 times the intensity of the Excitation Laser Beam. Furthermore, we have also directly measured thermo-plasmonic effects accompanying SPPs Excitation on gold submicron structures.
Horst-günter Rubahn - One of the best experts on this subject based on the ideXlab platform.
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Tailoring optical discs for surface plasmon polaritons generation.
Nanotechnology, 2019Co-Authors: Aleksandra Sierant, Roman Panaś, Jacek Fiutowski, Horst-günter Rubahn, Tomasz KawalecAbstract:The article reports on an optimization of gold submicron structures based on modified recordable blank digital versatile discs for surface plasmon polaritions Excitation, mainly in near-infrared region. We have examined internal layers of commercially available DVD+R, DVD-R, DVD+RW and DVD-RW optical discs and we have elaborated a simple, inexpensive approach providing sharp resonances with efficiency reaching 95% for collimated Excitation Laser Beams. We have experimentally and numerically confirmed the SPPs intensity being up to 220 times the intensity of the Excitation Laser Beam. We have also directly measured thermal energy loss accompanying SPPs Excitation.
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Surface Plasmon Polaritons Probed with Cold Atoms
Plasmonics, 2017Co-Authors: Tomasz Kawalec, Aleksandra Sierant, Roman Panaś, Jacek Fiutowski, Dobrosława Bartoszek-bober, L. Jozefowski, Horst-günter RubahnAbstract:We report on an optical mirror for cold rubidium atoms based on a repulsive dipole potential created by means of a modified recordable digital versatile disc. Using the mirror, we have determined the absolute value of the surface plasmon polariton (SPP) intensity, reaching 90 times the intensity of the Excitation Laser Beam. Furthermore, we have also directly measured thermo-plasmonic effects accompanying SPPs Excitation on gold submicron structures.
P. H. A. Mutsaers - One of the best experts on this subject based on the ideXlab platform.
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measurements of the energy distribution of a high brightness rubidium ion Beam
Ultramicroscopy, 2018Co-Authors: Ten G Haaf, S.h.w. Wouters, D. F. J. Nijhof, P. H. A. Mutsaers, E.j.d. VredenbregtAbstract:Abstract The energy distribution of a high brightness rubidium ion Beam, which is intended to be used as the source for a focused ion Beam instrument, is measured with a retarding field analyzer. The ions are created from a Laser-cooled and compressed atomic Beam by two-step photoionization in which the ionization Laser power is enhanced in a build-up cavity. Particle tracing simulations are performed to ensure the analyzer is able to resolve the distribution. The lowest achieved full width 50% energy spread is (0.205 ± 0.006) eV, which is measured at a Beam current of 9 pA. The energy spread originates from the variation in the ionization position of the ions which are created inside an extraction electric field. This extraction field is essential to limit disorder-induced heating which can decrease the ion Beam brightness. The ionization position distribution is limited by a tightly focused Excitation Laser Beam. Energy distributions are measured for various ionization and Excitation Laser intensities and compared with calculations based on numerical solutions of the optical Bloch equations including ionization. A good agreement is found between measurements and calculations.
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cavity enhanced photoionization of an ultracold rubidium Beam for application in focused ion Beams
Physical Review A, 2017Co-Authors: Ten G Haaf, S.h.w. Wouters, P. H. A. Mutsaers, E.j.d. VredenbregtAbstract:A two-step photoionization strategy of an ultracold rubidium Beam for application in a focused ion Beam instrument is analyzed and implemented. In this strategy the atomic Beam is partly selected with an aperture after which the transmitted atoms are ionized in the overlap of a tightly cylindrically focused Excitation Laser Beam and an ionization Laser Beam whose power is enhanced in a build-up cavity. The advantage of this strategy, as compared to without the use of a build-up cavity, is that higher ionization degrees can be reached at higher currents. Optical Bloch equations including the photoionization process are used to calculate what ionization degree and ionization position distribution can be reached. Furthermore, the ionization strategy is tested on an ultracold Beam of $^{85}\mathrm{Rb}$ atoms. The Beam current is measured as a function of the Excitation and ionization Laser Beam intensity and the selection aperture size. Although details are different, the global trends of the measurements agree well with the calculation. With a selection aperture diameter of $52\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{m}$, a current of $\left(170\ifmmode\pm\else\textpm\fi{}4\right)$ pA is measured, which according to calculations is 63% of the current equivalent of the transmitted atomic flux. Taking into account the ionization degree the ion Beam peak reduced brightness is estimated at $1\ifmmode\times\else\texttimes\fi{}{10}^{7}$ A/(${\mathrm{m}}^{2}\phantom{\rule{0.16em}{0ex}}\mathrm{sr}\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$).
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Measurements of the energy distribution of an ultracold rubidium ion Beam
arXiv: Atomic Physics, 2017Co-Authors: G. Ten Haaf, S.h.w. Wouters, D. F. J. Nijhof, P. H. A. Mutsaers, E.j.d. VredenbregtAbstract:The energy distribution of an ultracold rubidium ion Beam, which is intended to be used as the source for a focused ion Beam instrument, is measured with a retarding field analyzer. The ions are created from a Laser-cooled and compressed atomic Beam by two-step photoionization in which the ionization Laser power is enhanced in a build-up cavity. Particle tracing simulations are performed to ensure the analyzer is able to resolve the distribution. The lowest achieved full width 50% energy spread is $\left(0.205\pm0.006\right)$ eV. The energy spread originates from the variation in the ionization position of the ions which are created inside an extraction electric field. This extraction field is essential to limit disorder-induced heating which can decrease the ion Beam brightness. The ionization position distribution is limited by a tightly focused Excitation Laser Beam. Energy distributions are measured for various ionization and Excitation Laser intensities and compared with calculations based on numerical solutions of the optical Bloch equations including ionization. A good agreement is found between measurements and calculations.
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Two step photo-ionization of a Laser cooled and compressed thermal atomic Beam for use in a focused ion Beam
2016Co-Authors: G. Ten Haaf, S.h.w. Wouters, P. H. A. Mutsaers, Tim C.h. De Raadt, O.j. Luiten, E.j.d. VredenbregtAbstract:Photo-ionization is applied to a Laser cooled and compressed atomic rubidium Beam in order to generate a high brightness ion Beam. When focused, this ion Beam can be used to image and edit integrated circuits at the nano-scale which is important for the ongoing reduction of feature sizes in the semiconductor industry. Experiments have shown that an atomic Beam brightness in excess of 106 A/(m2 sr eV) can be achieved with a flux equivalent to 500 pA in a compact magneto-optical compressor which should be sufficient to generate ion spots of 1 nm. Currently, photo-ionization experiments are being carried out that aim at ionizing the majority of the atoms within a small longitudinal range in order to minimize the longitudinal energy spread. The two step ionization setup uses a tightly focused Excitation Laser Beam and a powerful blue Laser coupled to a build-up-cavity.
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Optimization of the current extracted from an ultracold ion source
New Journal of Physics, 2012Co-Authors: N. Debernardi, P. H. A. Mutsaers, O.j. Luiten, R.w.l. Van Vliembergen, W.j. Engelen, K.h.m. Hermans, M.p. Reijnders, S.b. Van Der Geer, E.j.d. VredenbregtAbstract:Photoionization of trapped atoms is a recent technique for creating ion Beams with low transverse temperature. The temporal behavior of the current that can be extracted from such an ultracold ion source is measured when operating in the pulsed mode. A number of experimental parameters are varied to find the conditions under which the time-averaged current is maximized. A dynamic model of the source is developed that agrees quite well with the experimental observations. The radiation pressure exerted by the Excitation Laser Beam is found to substantially increase the extracted current. For a source volume with a typical root-mean-square radius of 20µm, a maximum peak current of 88pA is observed, limited by the available ionization Laser power of 46mW. The optimum time-averaged current is 13pA at a 36% duty cycle. Particle-tracking simulations show that stochastic heating strongly reduces the brightness of the ion Beam at higher current for the experimental conditions.
Hiroaki Misawa - One of the best experts on this subject based on the ideXlab platform.
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Photoelectrochemical submicrometer patterning of titanium dioxide by platinum
Journal of Electroanalytical Chemistry, 1999Co-Authors: Saulius Juodkazis, Hidekazu Ishii, Shigeki Matsuo, Hiroaki MisawaAbstract:Abstract Submicrometer patterning of the TiO2-rutile single crystal surface by Pt was accomplished by means of photo-catalytic reduction of PtCl42− from aqueous solutions of H2PtCl6. The patterns of Pt were fabricated along focal point traces of a 380 nm wavelength Excitation Laser Beam. Single particles of Pt as small as 100 nm can be grown by such techniques.
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Photoelectrochemical Fabrication of Submicrometer Platinum Pattern on Titanium Dioxide Single Crystal Surface
Chemistry Letters, 1998Co-Authors: Hidekazu Ishii, Shigeki Matsuo, Saulius Juodkazis, Hiroaki MisawaAbstract:Submicrometer patterning of TiO2-rutile single crystal surface by Pt was accomplished by means of photocatalytic reduction of PtCl2−4 to Pt in an aqueous solution of H2PtCl6. The patterns of Pt were fabricated along focal point traces of 380 nm wavelength Excitation Laser Beam on the surface of rutile substrates.
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Three‐dimensional optical trapping and Laser ablation of a single polymer latex particle in water
Journal of Applied Physics, 1991Co-Authors: Hiroaki Misawa, Masanori Koshioka, Keiji Sasaki, Noboru Kitamura, Hiroshi MasuharaAbstract:We developed a Laser trapping‐ablation system comprised of CW and pulsed Nd3+:YAG Lasers as well as of an optical microscope. Three‐dimensional manipulation of various kinds of particles and Laser ablation of a single optically trapped, poly(methyl methacrylate) latex particle in water were demonstrated. A minute hole with its diameter of ∼sub‐μm was fabricated on the latex particle (∼6 μm diameter). The hole size produced was much smaller than the effective diameter of the Excitation Laser Beam, suggesting nonlinear optical (self‐focusing of the Laser Beam) and photochemical (multiphoton absorption) mechanisms for the present Laser trapping ablation. Characteristic features of the Laser trapping‐ablation are discussed in detail.
