The Experts below are selected from a list of 4909233 Experts worldwide ranked by ideXlab platform
G. Klemz - One of the best experts on this subject based on the ideXlab platform.
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Generation of flat-top picosecond pulses by coherent pulse stacking in a multicrystal birefringent filter.
Optics express, 2008Co-Authors: Ingo Will, G. KlemzAbstract:This paper deals with the pulse-shaping properties of birefringent filters that feature an optical layout similar to a Solc fan filter. A simple computational model is given that explains the pulse-shaping process in the fan filter in two steps: First, the input pulse is split into several mutually delayed replicas due to the birefringence of the crystals. Second, these replicas interfere at the output polarizer of the filter and form the shaped output pulse. Fine-tuning of the phases of the replicas of the input pulse is permitted by tuning the temperature of the crystals. A birefringent pulse Shaper containing ten birefringent crystals was investigated experimentally. The shape of the output pulses was measured by means of a special cross-correlation technique. Although a variety of pulse shapes can be generated with the described filter, it is particularly well suited for generation of flattop pulses featuring a 20-ps-long plateau and rising and falling edges shorter than 2 ps.
Manoel Damiao Sousaneto - One of the best experts on this subject based on the ideXlab platform.
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micro computed tomographic evaluation of the shaping ability of xp endo Shaper irace and edgefile systems in long oval shaped canals
Journal of Endodontics, 2017Co-Authors: Marco Aurelio Versiani, Kleber Kildare Teodoro Carvalho, Jardel Francisco Mazzichaves, Manoel Damiao SousanetoAbstract:Abstract Introduction This study evaluated the shaping ability of the XP-endo Shaper (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland), iRaCe (FKG Dentaire SA), and EdgeFile (EdgeEndo, Albuquerque, NM) systems using micro–computed tomographic (micro-CT) technology. Methods Thirty long oval-shaped canals from mandibular incisors were matched anatomically using micro-CT scanning (SkyScan1174v2; Bruker-microCT, Kontich, Belgium) and distributed into 3 groups (n = 10) according to the canal preparation protocol (ie, XP-endo Shaper, iRaCe, and EdgeFile systems). Coregistered images, before and after preparation, were evaluated for morphometric measurements of the volume, surface area, structure model index (SMI), untouched walls, area, perimeter, roundness, and diameter. Data were statistically compared between groups using the 1-way analysis of variance post hoc Tukey test and within groups with the paired sample t test (α = 5%). Results Within groups, preparation significantly increased all tested parameters (P .05). The XP-endo Shaper significantly altered the overall geometry of the root canal to a more conical shape (SMI = 2.59) when compared with the other groups (P .05). Conclusions The XP-endo Shaper, iRaCe, and EdgeFile systems showed a similar shaping ability. Despite the XP-endo Shaper had significantly altered the overall geometry of the root canal to a more conical shape, neither technique was capable of completely preparing the long oval-shaped canals of mandibular incisors.
Ingo Will - One of the best experts on this subject based on the ideXlab platform.
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Generation of flat-top picosecond pulses by coherent pulse stacking in a multicrystal birefringent filter.
Optics express, 2008Co-Authors: Ingo Will, G. KlemzAbstract:This paper deals with the pulse-shaping properties of birefringent filters that feature an optical layout similar to a Solc fan filter. A simple computational model is given that explains the pulse-shaping process in the fan filter in two steps: First, the input pulse is split into several mutually delayed replicas due to the birefringence of the crystals. Second, these replicas interfere at the output polarizer of the filter and form the shaped output pulse. Fine-tuning of the phases of the replicas of the input pulse is permitted by tuning the temperature of the crystals. A birefringent pulse Shaper containing ten birefringent crystals was investigated experimentally. The shape of the output pulses was measured by means of a special cross-correlation technique. Although a variety of pulse shapes can be generated with the described filter, it is particularly well suited for generation of flattop pulses featuring a 20-ps-long plateau and rising and falling edges shorter than 2 ps.
Jianping Yao - One of the best experts on this subject based on the ideXlab platform.
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all fiber ultrawideband pulse generation based on spectral shaping and dispersion induced frequency to time conversion
IEEE Photonics Technology Letters, 2007Co-Authors: Chao Wang, Fei Zeng, Jianping YaoAbstract:An approach to generating and distributing ultrawideband (UWB) pulses based on optical spectral shaping and frequency-to-time conversion using all-fiber components is proposed and demonstrated. In the system, the spectrum of an ultrashort pulse from a mode-locked fiber laser is spectrally shaped by an all-fiber spectrum Shaper, to produce a monocycle- or a doublet-shaped power spectrum. Thanks to the frequency-to-time conversion in a dispersive fiber, time-domain optical pulses exhibiting the user-defined shape of the optical power spectrum are obtained. Experiments based on the proposed approach are carried out. UWB monocycle or doublet pulses are generated
M Papini - One of the best experts on this subject based on the ideXlab platform.
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a rotating mask system for sculpting of three dimensional features using abrasive jet micro machining
Journal of Materials Processing Technology, 2017Co-Authors: M Sookhak R Lari, Ahad Ghazavi, M PapiniAbstract:Abstract Channels with non-conventional shaped cross sections have applications especially in microfluidics, where flow and heat transfer characteristics may depend on shape. Most microfabrication technologies capable of sculpting desired micro-channel shapes are limited in the range of shapes they can produce. Abrasive jet micromachining (AJM) uses a jet of impacting abrasive particles to mechanically etch the target surface. Its directional etch capability makes it well suited for the sculpting of a wide variety of micro-features with three-dimensional (3D) topographies. Elastomeric masks have in the past been used to define complex patterns in AJM applications. Traditionally, such masks have been applied directly to the target, but this only allows the AJM of shallow features without any control over their cross-sectional shape. This paper presents a new technique that allows the instantaneous AJM erosive footprint size and shape to be controlled using a novel rotating mask apparatus (RMA). Models for predicting the required rotating mask pattern required to create a desired footprint are also presented. The models were experimentally verified for symmetric and asymmetric W-shaped, trapezoidal and wedge shaped footprints. The benefits of the RMA include: (i) the ability to generate virtually any footprint, including those that mimic moving a source (e.g. nozzle) or multiple sources of various sizes instantly from one location to another; (ii) improved mask longevity; and (iii) use of traverses in a straight line, rather adjacent traverses, in order to sculpt desired 3D feature shapes.
